Calculation basis of the online calculators

Principles for all calculators

Preliminary sizing

The calculators provide guide values for comparing variants, quantities and estimates. They do not perform verifications according to DIN EN 13480, AD 2000 or ASME B31.3 and replace neither pipe stress analysis nor support design. Every result must be checked and approved before binding use.

Origin of the values

Each property value has one of three origins: Standard (method and formula, never standard tables), Data sheet (publicly available manufacturer data, generalized) or Guide value (generally common order of magnitude or ASEING experience value). The calculators mark guide values. Almost all property values can be changed in the calculator; in the Support Span Calculator, custom values for stress, modulus of elasticity and outside diameter can be stored.

Calculation in the browser

Every input triggers a full recalculation, entirely in the browser. Imported files (PCF, PDF, photos) are evaluated only in the browser and are not uploaded. The browser remembers your own values and additions on this device.

Same master data

In all calculators, pipe dimensions, wall thickness series, ASME sizes and schedules, materials and class ratings come from the Piping Spec Calculator. Densities of material, medium, insulation and cladding as well as the modulus of elasticity versus temperature come from the Support Span Calculator. Each value thus has exactly one source.

Data transfer

A piping spec created in the Piping Spec Calculator is available in the pressure drop and pipe weight calculators as a separate pipe series “Current piping spec” (outside diameters and wall thicknesses per DN). Material, temperature, pressure, corrosion allowance, DN range and wall thicknesses are passed to the Support Span Calculator. With a customer account, PCF files (e.g. isometric export from AutoCAD Plant 3D) can be imported; piping spec, material, service, insulation thickness, pipe lengths per DN, fittings, valves, weights and elevation are transferred. What each calculator uses is described with the respective calculator.

Figures and tables

Decimal commas or points are accepted. Values between table entries are interpolated linearly; outside a table, the boundary value applies and no extrapolation takes place. Where a calculator computes beyond the table range, it indicates this.

Verifiable

Under every result for pressure drop, thermal expansion, pipe weight, PN ↔ Class and pipe marking tape, an expandable “Check calculation method” section shows each formula with the values used, the result and the source of each property value, also as a PDF. With every build of the website, fixed test cases recalculate all calculators against an independent reference calculation (tolerance 0.1 %); an error stops publication. The result is shown in the test report of the online calculators.

Governing

For design and ordering, the manufacturers' data and the currently valid standard apply (see General Terms and Conditions, clause 6.7). The current standards status is shown in Chapter 14.

Pipe sizing and pressure drop

The calculator finds the appropriate nominal size of a pipe series from the flow rate and permissible velocity. It then estimates the pressure drop of a line with fittings, valves and difference in elevation.

How the calculation works

1. Fluid properties: water – density ρ and kinematic viscosity ν from a table, linearly interpolated over temperature. Gases – ideal gas with fixed dynamic viscosity μ. Other media – fixed values.
2. Operating volume flow Q in m³/s from the selected unit (m³/h, l/s, kg/h or Nm³/h).
3. For each nominal size in the series: inside diameter, velocity, Reynolds number, friction factor λ and pressure gradient.
4. Selection: The smallest DN with v ≤ v_zul is recommended.
5. Line: pipe friction, individual resistances and elevation component are added.

d_i = d − 2·s [mm]
A = π/4 · d_i² [m²]
v = Q / A [m/s]
Re = v · d_i / ν

laminar (Re < 2320): λ = 64 / Re
turbulent (Colebrook-White): 1/√λ = −2 · log₁₀( k/(3.71·d_i) + 2.51/(Re·√λ) )

Colebrook-White is solved iteratively: initial value λ = 0.02, termination at a change below 10⁻⁹ or after 40 steps. There is no separate transition range; from Re = 2320, Colebrook-White applies.

Pressure gradient R = λ/d_i · ρ·v²/2 [Pa/m] (displayed in bar/100 m and mbar/m)
Δp_R = R · L
Δp_E = Σζ · ρ·v²/2
Δp_G = ρ · g · Δh (Δh positive upwards; g = 9.81 m/s²)
Δp = Δp_R + Δp_E + Δp_G Pump head H = Δp / (ρ·g)

Gas: p_abs = (p_ü + 1.01325) · 10⁵ Pa, T = t + 273.15 K, ρ = p_abs / (R_s·T), ν = μ/ρ
Nm³/h: Q = q · ρ_N / (3600 · ρ) with ρ_N at 0 °C and 1.01325 bar

For gas, the elevation component is omitted and no pump head is output. The table shows nominal sizes with 0.05 m/s ≤ v ≤ 3·v_zul; rows above v_zul are shown in grey.

Worked example

Defaults and guide values

Pipe series: steel pipe EN 10220 with ferritic minimum structural wall thickness, stainless steel pipe EN ISO 1127 with austenitic minimum wall thickness, ASME B36.10 Schedule STD, ASME B36.19 Schedule 10S, PE 100 SDR 11, hygienic tube DIN 11850 series 2, plus the current piping spec and the piping spec from a PCF. The steel and stainless steel series also contain the nominal sizes that should be avoided where possible according to DIN EN 10220 (e.g. DN 65, DN 125); they are marked and not recommended – the next preferred nominal size is recommended.

Transfer from the PCF

• Piping spec from the pipe descriptions (outside diameter × wall thickness per DN), roughness via the material family.
• Medium via keywords in service and line name (e.g. heiz, kw, wasser → water; druckluft → compressed air; n2 → nitrogen; glykol, sole → glycol; öl → hydraulic oil).
• Length of the main nominal size (largest pipe length); further nominal sizes are reported for separate calculation.
• 90° and 45° elbows, tees (as run) and reducers of all nominal sizes; valves by SKEY or description (butterfly valve, ball valve, gate valve, check valve, strainer, globe valve). Elbows with other angles, flanges and 3-way valves are not transferred – add values according to manufacturer data.
• Elevation is displayed; the designer enters the difference in elevation in the direction of flow.

Limits

• Applies to incompressible flow with one nominal size per calculation. Gases only with small pressure drop: from Δp > 10 % of the absolute operating pressure, the calculator issues a warning – then calculate section by section.
• Water temperature 0–200 °C; outside this range the boundary value applies with a warning. The water values and the gas viscosity are temperature-dependent; glycol and hydraulic oil apply to the stated temperature.
• Plastic series with water or gas: warning “Not usable like this” below −20 °C or above 60 °C (PE 100 as pressure pipe up to approx. 40 °C; manufacturer data are authoritative).
• Not calculated: steam, two-phase flow, bulk solids, pump curve and NPSH, K_v approach for control valves.

Background

The pressure drop of straight pipes follows the Darcy-Weisbach approach: it increases with length and dynamic pressure and decreases with the inside diameter. The friction factor λ depends on the Reynolds number and the relative roughness k/d_i; the Colebrook-White equation links smooth and rough behaviour and forms the basis of the Moody diagram. The critical Reynolds number is given in the literature as 2300 or 2320. Individual resistances are captured as multiples of the dynamic pressure; their coefficients depend strongly on design and nominal size.

Pipe sizing & pressure drop ›

Background according to KSB: centrifugal pump handbook (pipe friction, ζ values, velocities), Wikipedia: pipe friction factor, Wikipedia: Darcy friction factor formulae, TU Graz: properties of water and air

Thermal expansion, expansion joint and flexible leg

The calculator determines the change in length between two anchor points from the installation, minimum and maximum temperatures. From this follow the movement absorption of an expansion joint with pre-set and an initial estimate for L, Z and U bends.

How the calculation works

The coefficient of thermal expansion ᾱ is the mean value from 20 °C to temperature t. Each expansion is therefore referred to 20 °C and the difference is then taken.

ΔL(t) = L · ᾱ(t) · (t − 20 °C) [L in mm, ᾱ in 10⁻⁶/K]
Expansion installation → T_max: Δ_aus = ΔL(T_max) − ΔL(T_M)
Contraction installation → T_min: Δ_ein = ΔL(T_M) − ΔL(T_min)
Total movement Δ_ges = Δ_aus + Δ_ein

Expansion joint: movement absorption ≥ 1.1 · Δ_ges (10 % reserve)
Pre-set: v = Δ_aus − Δ_ges/2 (v ≥ 0: pull apart during installation, v < 0: compress)

Flexible leg, metal (guided cantilever): σ = 3·E·D·δ / L² ⇒ L = √(3·E·D·δ / σ_zul)
Flexible leg, plastic: L = C · √(D·δ) (C according to manufacturer documentation, DVS 2210-1)
δ = Δ_ges for L and Z bends, δ = Δ_ges/2 per leg for U bends
E and σ in N/mm², L, D and δ in mm

An entered α replaces the table value for T_max; for installation and minimum temperature, the table value remains. The modulus of elasticity applies at 20 °C – this is also how displacement stress is calculated in pipe stress analysis (ASME B31.3: E at installation temperature); a user-defined value takes precedence. The constants for plastics: PE 26, PP 30, PVC-U 33.5, PVDF 21.6 (Sikla, Chapter 18 Piping technology); if both E and σ are entered, the calculator also treats plastic as a guided cantilever.

Worked example

Defaults and guide values

Transfer from the PCF

Material family from the material of the line (1.4571, other stainless steel, copper, plastic as PE 100, otherwise steel), length of the longest straight leg and outside diameter of the main nominal size. A straight leg comprises parallel, adjoining pipes, flanges, valves and reducers. The anchor points are defined by the support design; the length must therefore be adjusted if necessary.

Limits

• If a temperature lies outside the application range, the calculator marks the result with “Not usable like this”: it then only shows what the calculation would yield.
• Above the highest table value, the calculator uses the value of the last reference point and indicates this.
• Flexible leg as an estimate without bend flexibility, friction and support forces; L and Z bends are calculated identically. For verification according to DIN EN 13480-3 or ASME B31.3, use the allowable stress range; for plastics, the manufacturer's data or the DVS guideline.
• Not calculated: anchor point and expansion joint reaction forces, pressure thrust, support friction, stress verification.

Background

Material data sheets state the coefficient of thermal expansion as a mean value between 20 °C and the respective temperature. The change in length between any two temperatures is therefore the difference of two expansions referred to 20 °C. An expansion joint works best symmetrically around its mid-position; the pre-set during installation achieves this. With a flexible leg, a laterally displaced pipe leg absorbs the expansion. The “guided cantilever” model (both ends restrained against rotation) gives the constant 3; approaches using a free cantilever result in shorter legs, so the calculator is on the safe side.

Thermal expansion ›Support Span Calculator ›

Background according to Swiss Steel: data sheet 1.4404, Sikla: piping technology, Engineers Edge: L bend as guided cantilever, whatispiping: Guided Cantilever Method, Witzenmann: operating and installation instructions for expansion joints

Pipe weight and support load

The calculator determines the weight per metre from pipe, contents, insulation and cladding. From this follows the load per support for operation and hydrostatic test.

How the calculation works

Pipe: m_R = ρ_R · π/4 · (d² − d_i²) · 10⁻⁶ [kg/m; dimensions in mm, ρ in kg/m³]
Contents: m_F = ρ_F · π/4 · d_i² · 10⁻⁶ Water hydrotest: m_W with 1000 kg/m³
Insulation: D_i = d + 2·s_i, m_I = ρ_I · π/4 · (D_i² − d²) · 10⁻⁶
Cladding: m_J = ρ_J · π · (D_i + t_J) · t_J · 10⁻⁶ (only with insulation)

Operation: q_B = m_R·(1 + Z/100) + m_F + m_I + m_J
Hydrotest: q_P = m_R·(1 + Z/100) + max(m_F; m_W) + m_I + m_J
Load per support: F = (q · L_s + m_Einzel) · g / 1000 [kN]

Z is the allowance for flanges and fittings on the pipe weight, L_s the support span (tributary length = support span), m_Einzel a point load per span, e.g. a valve. All values are shown with two decimal places.

Whole line from the PCF: pipes with length per DN × weight per metre of the selected piping spec, without allowance; fittings, flanges and valves with the weights from the PCF. Missing valve weights can be added per valve. Gaskets and bolts are not included. Empty = Σ pipe + parts, operating = empty + contents + insulation, hydrotest = empty + max(contents; water) + insulation.

Worked example

Defaults and guide values

Cladding (thickness / density): aluminium 0.8 mm / 2700 kg/m³ (default) · galvanized steel 0.75 mm / 7850 kg/m³ · stainless steel 0.5 mm / 7900 kg/m³ · PVC film 0.35 mm / 1400 kg/m³. Further defaults: insulation thickness 50 mm, allowance 10 %, support span 5 m, hydrotest with water 1000 kg/m³. The glycol value is on the safe side for weights. All densities are guide values and adjustable in the calculator.

Limits

• Load per support as distributed load × support span: end and interior spans and continuous beam effects are not distinguished. End supports and supports next to valves carry more.
• At anchor points, friction, expansion and internal pressure forces are added; wind, snow, ice and dynamic loads are not included.
• The hydrostatic test is often governing for gas and steam lines – both load cases are shown side by side.

Pipe weight ›Support Span Calculator ›

Background according to TRR 100, explanatory notes on 6.22 (support spans), Rockwool: environmental product declaration, medium-density mineral wool, Swiss Steel: data sheet 1.4301

Support spans

The Support Span Calculator determines the permissible support span of straight steel piping from dead weight, contents, insulation, additional and point load. It outputs a support span sheet with table, diagram and calculation appendix. The criteria are explained in Chapter 07, Support spans.

How the calculation works

1. Wall thickness: taken from the Piping Spec Calculator or entered per row, otherwise the minimum structural wall thickness.
2. Distributed load q = (m_R + m_F + m_I + m_J + m_Zusatz) · g / 1000 in N/mm, masses as for pipe weight.
3. Cross-section: moment of inertia from the nominal wall thickness, section modulus from the wall thickness reduced by the negative tolerance and corrosion allowance.
4. Criteria as a function of L, for each criterion the largest permissible length up to 40 m (bisection).
5. Governing is the smallest value; the support span is rounded down to the selected step (0.1 / 0.25 / 0.5 m).

I = π/64 · (D⁴ − d_i⁴)
e = T − c₁ − c₂, Z = π/(32·D) · (D⁴ − (D − 2e)⁴)
c₁ ferritic = max(0.4 mm; 12.5 % · T), otherwise 10 % · T

Deflection: f = k_f·q·L⁴/(E·I) + k_fF·F·L³/(E·I) ≤ min(f_abs; L/n)
Stress: p·D/(4·e) + M/Z ≤ f_h, M = k_M·q·L² + k_MF·F·L (straight pipe 0.75·i = 1.0)
Slope: θ = k_T·q·L³/(E·I) + k_TF·F·L²/(E·I) ≤ slope
Upper limit: L ≤ L_max

The allowable stress follows the same approach as in the Piping Spec Calculator: ferritic and nickel f₂₀ = min(R_p/1.5; R_m/2.4), austenitic R_p1,0/1.5, copper R_m/3.5; f(t) = f₂₀ · k(t), multiplied by the selected utilization. The point load F acts at mid-span; the maxima from distributed and point load are superimposed.

Defaults and example

Defaults: material 1.4541, 100 °C, 10 bar, c₂ = 0, DN 15–600, water, mineral wool pipe section 50 mm with aluminium cladding 0.8 mm, single-span beam, permissible deflection 5 mm, utilization 100 %, structural upper limit 12 m, rounding 0.1 m. The modulus of elasticity follows the table under Thermal expansion.

Limits

• Applies to straight runs without fittings. Changes in direction, branches, flanges and valves shorten the support span.
• Thermal expansion, friction, wind, snow, earthquake, pressure surges, support loads and stability must be verified separately. Stress intensification factors are taken as i = 1.
• Ferritic materials from 380 °C: note on creep effects, which are not part of the preliminary sizing.
• For small nominal sizes, some codes specify stricter deflection limits than 5 mm – the value is adjustable.
• No separate load case for the hydrostatic test; select water as the medium instead. The Support Span Calculator does not calculate plastic, GRP or ASME series.

Supports tab in the Piping Spec Calculator: It outputs a simplified support span for each nominal size – single-span beam with f = 5 mm, E at 20 °C, insulation 100 kg/m³ without cladding, max. 12 m, without stress verification: L_s = (384·E·I·f / (5·q))^¼, rounded down to 0.1 m. For the support span sheet, the Support Span Calculator applies.

Background

The support span results from deflection, stress and slope. Deflection limits water pockets and ensures drainage. For the stress due to sustained loads, DIN EN 13480-3 adds the longitudinal stress from internal pressure and the bending stress from weight; for straight pipes, the factor 0.75·i is taken as 1.0. The calculator uses the reduced wall thickness and is therefore on the safe side.

Support Span Calculator ›Piping Spec Calculator ›

Background according to TRR 100, explanatory notes on 6.22, SST Systems: Readme Supplement (EN 13480-3, Eq. 12.3.2-1), CodeCogs: beam formulas, structuralbasics: deflection

Wall thickness per code (Piping Spec Calculator)

The Piping Spec Calculator determines the required wall thickness for each nominal size, selects an order wall thickness from a dimension series and outputs allowable pressure, utilization, fittings, branch table, vacuum resistance and availability. The structure and content of a piping spec are explained in Chapter 08.

How the calculation works (metric)

1. Temperature: design temperature, limited to the application limit of the material (with a note). A note appears from the creep range of the material onwards.
2. Pressure-temperature table: at each reference point, PN constant or derated by f(t)/f(20 °C), rounded to 0.1 bar. Alternatively, a fixed design point (pressure, temperature) applies.
3. Governing point: Start at the point closest to 20 °C; another point only becomes governing if its ratio p/f is more than 0.5 % higher.
4. Required wall thickness e according to the formula of the code.
5. Order wall thickness T: first wall thickness in the series within the available range for the DN with T ≥ T_min and e_a ≥ e. No match in the available range: “custom-made”; if no wall thickness is sufficient: “not sufficient”.
6. Allowable pressure with e_a of the order wall thickness; utilization = p / p_zul.
7. Fittings (elbow, reducer, cap) using in-house formulas, selected from the fittings list, at least pipe wall thickness.

Negative tolerance c₁: ferritic max(0.4 mm; 12.5 % · T), others 10 % · T
e_a = T − c₁ − c₂

c₂ is the corrosion or wear allowance (designation as in AD 2000; in DIN EN 13480-3 this allowance is called c₀). The weld joint factors z (EN) or v (AD, DIN) are entered as input, default 1.0, for hygienic tube 0.85 for the longitudinal seam. Validity limits of the formula for thin-walled pipes: EN 13480 D_a/D_i ≤ 1.7, AD 2000 ≤ 1.2; above that a note appears.

Worked example

Defaults and guide values

• Material properties (R_eH or R_p1,0, R_m at 20 °C, temperature factors, application limits): estimates from publicly available manufacturer catalogs or guide values from the material standards for wall thicknesses up to 16 mm; nickel alloys according to VdTÜV material data sheets (minimum values).
• Availability (ASEING experience values): in the stock range up to DN 200 “stock item”, up to DN 600 “available on the market”, above that “on request”; outside the available wall thickness range “custom-made”. Nickel and copper always “on request”.
• Safety factor of the spec (AD 2000 and DIN 2413 only): f = f(t) · 1.5 / S_Klasse, separate factor for branches and caps.

ASME B31.3

t = P·D / (2·(S·E·W + P·Y)), W = 1, Y = 0.4, E = weld joint factor
e_a = T·(1 − 12.5 %) − c, P_zul = 2·S·E·e_a / (D − 2·Y·e_a)
Bend (304.2.1): I = (4·R/D − 1)/(4·R/D − 2), t_B = P·D / (2·(S·E·W/I + P·Y))

The allowable stress S is interpolated over reference points from 38 to 427 °C (guide values according to Table A-1, e.g. A106 B at 38 °C 137.9 N/mm²); below 38 °C, the 38 °C value applies. The first schedule with sufficient wall thickness is selected; for ferritic materials only carbon steel schedules. Minimum schedule (common company-standard practice): ferritic up to NPS 1½ Sch 80, up to NPS 12 STD, above that Sch 10; austenitic up to NPS 1½ 40S, above that 10S. Fittings receive the schedule of the pipe; the elbow wall thickness is only reported.

Plastic

σ(t) = σ₂₀ · k(t) · f_Medium, σ₂₀ = MRS / C
e = p·d / (2·σ + p)
Wall thickness of the series: w = max(e_min; ⌈d/SDR · 10⌉/10)
selected: largest SDR with w ≥ e / 1.025

The 2.5 % compensates for the rounding of the standardized PN/SDR assignment. For small diameters up to d 40, the thickest standard series applies as the minimum series. The reduction factor for the medium (f_CR ≤ 1) is adjustable.

Hygienic, copper, GRP

• Hygienic: fixed wall thicknesses to DIN 11850 series 2 (e.g. DN 50 53 × 1.5, DN 100 104 × 2.0), calculation as EN 13480 with z = 0.85. Notes: internal roughness R_a ≤ 0.8 µm, fittings DIN 11852, DIN 11851 unions and DIN 32676 clamps are not aseptic (use DIN 11864 instead). Sealing ring EPDM up to 140 °C, above that or for aggressive media FKM.
• Copper: wall thicknesses to DIN EN 1057, f = R_m(t)/3.5; limits of the joint type (press fitting, soft or hard solder) are checked.
• GRP: no strength calculation; the catalog wall thickness and catalog PN of the system apply.

Branches and vacuum

Branch (pressure area method, simplified according to EN 13480-3 or AD 2000 B9):
l_so = √((2·r_is + e_as)·e_as), l_bo = √((2·r_ib + e_ab)·e_ab)
A_ps = r_is·(l_so + r_ib), A_pb = r_ib·(l_bo + e_as), A_fs = e_as·l_so, A_fb = e_ab·l_bo
satisfied if (A_fs + A_fb)·(f − 0.5·p) ≥ p·(A_ps + A_pb)

The branch table marks each run/branch combination: A = set-on, verification satisfied · B = reinforced nozzle with wall thickness · TA/TB = tee according to fittings standard type A/B (up to three DN steps) · X = to be specified during design. ASME calculates area replacement according to 304.3.3 (90°, without reinforcing pad).

Vacuum (long cylinder, elastic, safety factor 3, ν = 0.3):
p_zul = 2·E/(1 − ν²) · (e_a/D_a)³ / 3 ≥ 0.1 N/mm² ⇒ “−1.0 bar” (full vacuum)

Limits

• Not calculated: creep (note only), cyclic loading, thick-walled pipes beyond the validity limit, flange strength and leak-tightness according to DIN EN 1591-1, chemical resistance, pipe stress analysis.
• Plastic: no vacuum verification, no branch calculation. GRP: strength, negative pressure and axial forces according to manufacturer data.
• Fitting wall thicknesses for dimension series (hygienic, copper, GRP) and ASME correspond to the pipe wall thickness.

Background

All codes size the straight pipe under internal pressure using a boiler formula. They differ mainly in the allowable stress: DIN EN 13480-3 uses yield strength and tensile strength with partial safety factors of 1.5 and 2.4, AD 2000 the strength value K at design temperature with S = 1.5, ASME B31.3 tabulated allowable stresses. At the inner radius of the bend, the hoop stress increases; the intrados factor of the EN corresponds to factor I in ASME B31.3. Plastic pipes are sized using the long-term strength MRS and an overall service coefficient C.

Piping Spec Calculator ›Piping catalogs ›

Background according to EN 13480-3 draft prA5 (allowances, validity), HS Mittweida: comparison AD 2000 / EN 13445, Alleima: pressure calculation according to EN 13480, Engineering ToolBox: ASME B31.3, PE100+ Association, GF Piping Systems: system specification, Landefeld: copper pipe, Alfa Laval: DIN 11850 / EN 10357

Flange PN, flange dimensions and bolts

The Piping Spec Calculator assigns a flange pressure rating to each nominal size and uses it to compile the bolt set with length and material.

How the calculation works

• Flange PN (common practice to EN 1092-1): spec PN below 10 → PN 6; PN 40 and higher → same as spec; otherwise DN ≤ 40 → PN 40, DN ≤ 150 → at least PN 16, above that same as spec. Example PN 10: DN 15–40 with PN 40, DN 50–150 with PN 16, from DN 200 with PN 10.
• Plastic: flange PN = min(16; max(10; PN)); stub-end/backing flange usually up to PN 16.
• Flange dimensions per PN and DN: outside diameter, bolt circle, bolt hole diameter, number and thread of bolts, flange thicknesses for weld neck and blind flange – estimates from manufacturer catalogs referencing DIN EN 1092-1 (e.g. PN 16, DN 100: D 220, K 180, L 18, 8 × M16).

Clamping length flange–flange: k = C₂ + C₂ + s_Dichtung + n_Scheiben·h
Clamping length flange–blind flange: k = C₂ + C₄ + s_Dichtung + n_Scheiben·h
Hexagon bolt: L_min = k + m + 2·P → next preferred length
Stud bolt (from PN 63): L = k + 2·m + 4·P, rounded up to 5 mm

Limits

• No strength and leak-tightness verification of the flange joint (DIN EN 1591-1); no pressure-temperature rating of the EN flanges – PN is the allowable pressure at room temperature; at higher temperatures, EN 1092-1 derates per material group.
• From PN 160 onwards, the blind flange thicknesses are guide values; the calculator shows non-standardized blind flanges as missing.

Piping Spec Calculator ›

Background according to KVT: flange connection dimensions EN 1092, KSB pump lexicon: flange standard, Project Materials: bolt length, Hexagon: bolt length according to ASME B16.5

Application, media and PED category

From the selected medium, the Piping Spec Calculator derives the fluid group, aggressiveness, gasket, valve design and bolting. It suggests suitable material systems and connections and assigns the line to a category of the Pressure Equipment Directive. How one piping spec covers several media is shown in Chapter 08, Media and media groups.

How the calculation works

• Medium: 33 stored media with state of aggregation, fluid group, aggressiveness class, density and suggested design temperature; media groups according to DIN 2403. Properties (acidic, alkaline, food-grade, hazardous) act like an additional medium.
• Several media: gaseous if one medium is gaseous; fluid group 1 if one medium has it; highest aggressiveness, highest temperature, greatest density. For suitability, the strictest rating prevails (not suitable before conditionally suitable before suitable).
• State of aggregation: Above a limit temperature, liquids are treated as gases, e.g. water from 110 °C (vapour pressure above 0.5 bar gauge).
• Material systems with temperature guide values: steel −10 … 450 °C · stainless steel −196 … 550 °C · copper −196 … 200 °C · plastic −20 … 140 °C · GRP −30 … 110 °C · hygienic −10 … 150 °C. Outside these ranges, the system is considered unsuitable.
• PED: Input variables are PS, DN and PS·DN, state of aggregation and fluid group. The classification follows Article 4(3) and Annex II, Tables 6 to 9; for group 2 gases above 350 °C, category II becomes III. Below PS = 0.5 bar, the line is not pressure equipment piping.

• Valve: critical – bellows or stuffing box with verification to DIN EN ISO 15848-1, seat leakage rate A to DIN EN 12266-1; M2 – stuffing box with PTFE or graphite packing; otherwise graphite packing.
• Bolts: critical – reduced-shank bolts or verification of the gasket surface pressure to DIN EN 1591-1 with controlled tightening; otherwise hexagon bolts.
• Insulation requirement: TS ≥ 60 °C required (touch protection, surface ≤ 60 °C); heating, hot and drinking water from 30 °C according to GEG Annex 8; TS < 12 °C required (dew point, vapour barrier); 40–60 °C recommended. GEG thickness at λ = 0.035 W/(m·K) from the inside diameter: up to 22 mm → 20 mm, up to 35 mm → 30 mm, up to 100 mm → d_i rounded up to 10 mm, above that 100 mm.
• Suggested code: up to 0.5 bar no pressure equipment (flue gas to DIN EN 1443 / 1856); above that DIN EN 13480-3, alternatively AD 2000, for ASTM materials ASME B31.3.

Limits

• Suitability is an ASEING preselection based on publicly available manufacturer data, not a resistance test. Every statement carries an identifier; rules not yet technically confirmed are shown by the tool with “Rule not yet technically reviewed”.
• The PED category is a suggestion; the boundary lines apply according to the tables in the Official Journal. The calculator does not evaluate notes on unstable gases – classify such media separately.

Piping Spec Calculator ›

Background according to PED 2014/68/EU Art. 4, PED Annex II, TRGS 201 Annex 3 (DIN 2403), Wagner: Rohrleitungstechnik (sample pages)

Converter for DN, schedule, PN/Class and materials

Four tabs connect the European and the American world: DN ↔ NPS, schedule ↔ wall thickness, PN ↔ Class with rating, and material ↔ ASTM. All data come from the Piping Spec Calculator. The dimension table is in Chapter 07.

How the calculation works

• DN ↔ NPS: Search by DN (“DN 100”), NPS (“4"”, “1 1/2"”) or outside diameter. Without a prefix, a row matches on equal DN, equal NPS text or an outside diameter within ±0.6 mm (hygienic tube ±0.3 mm). Equal DN does not mean equal outside diameter: DN 65 = 76.1 mm (EN) or 73.0 mm (ASME), DN 125 = 139.7 or 141.3 mm.
• Schedule ↔ wall thickness: all schedules of a size with inside diameter d − 2t and steel weight 7850 · π/4 · (d² − d_i²) · 10⁻⁶ kg/m. For an entered wall thickness, the calculator shows the closest schedule and the closest standardized EN wall thickness.
• PN ↔ Class: rating of the material group versus temperature, linearly interpolated; Class 150 and 300 from in-house tables, higher classes as multiples of Class 300. The smallest class whose rating reaches the required pressure is selected.
• Material ↔ ASTM: partial text search in material number, short name, old names and pipe standard; displays the comparable ASTM pipe, fitting and flange material.

Stored equivalents (selection): 1.0345 P235GH → A106 Gr. B · 1.4301 → TP304 · 1.4307 → TP304L · 1.4401 → TP316 · 1.4404 → TP316L · 1.4541 → TP321. “Comparable” means similar composition, not equivalent: strength values, scope of testing and approval differ.

Limits

• Ratings for groups 1.1 and 2.1 to 2.4 from 38 to 425 °C; below 38 °C, the 38 °C value applies; above 425 °C, the calculator does not output a rating. Class 400 = 4/3 · Class 300.
• Class 150 and PN 16, or Class 300 and PN 40, cannot be connected (different bolt circles). No EN 1092-1 rating, no flange dimensions.
• Schedules with “S” apply only to stainless steel pipes (ASME B36.19).

Unit converter ›

Background according to Project Materials: EN 10220 / ISO 1127, Project Materials: ASME B36.10/B36.19, Wermac: ASME B16.5 Ratings, Engineering ToolBox: PN and Class, Global Seamless: EN 10216

Identification generator

The generator assembles identification codes according to DIN 2403, KKS, AKS and RDS-PP and checks their structure. It is a simulation for teaching purposes, not for identification in operation. The systems are explained in Chapter 03.

DIN 2403 – pipe marking tape

Rings: n = max(2; ⌈L/10 m⌉ + 1) + number of valves and penetrations
Tape length per ring: π · d_a + 30 mm overlap (d_a incl. insulation)
Total tape: n · tape length

Example: 40 m line, d_a 60.3 mm, 4 valves → 5 + 4 = 9 rings of 219 mm each, a total of 2.0 m of tape. Tape width (calculator guide value): 76 mm, with additional color 100 mm. The group is set if the substance name appears unambiguously in the short example list; otherwise the designer selects it. Additionally mark hazardous substances with GHS pictograms. The screen colors are approximations of the RAL shades.

KKS, AKS, RDS-PP

• KKS: format check of level 0 (overall plant, 1 character) · prefix number · level 1 function (N)AAANN · level 2 equipment unit AANNN(A) · level 3 component AANN; levels 2 and 3 may be omitted. The calculator interprets a single digit before the first function letter as a prefix number, a letter as the overall plant. A dot indicates the point of installation code. Plain-text descriptions come from an extract of the codes; the code letters are only checked formally.
• AKS: Example structure with 11 levels and 29 characters (country, location, building, floor, documentation status, cost group DIN 276, system, assembly, equipment, data point). The number of characters per level is checked. The client's AKS guideline is authoritative.
• RDS-PP / DIN EN IEC 81346: prefix “=” function, “−” product, “+” location, optionally preceded by “#” for the plant assignment (assumption – the notation is defined by the operator's guideline). Prefixes and capitalization are checked, not the class code letters.

Limits

No standard texts and no VGB code list. Binding are the current DIN 2403, the code section of VGB-S-811-01, DIN EN IEC 81346 with ISO 81346-10 and the client's guideline.

Plant Identification Generator ›

Groups, colors and code texts according to Wikipedia: DIN 2403 and Wikipedia: Power plant classification system (KKS) (CC BY-SA 4.0), generalized; TRGS 201 Annex 3, Wikipedia: IEC 81346

Scan project estimator

For a laser scanning project, the estimator determines scan positions, days on site, registration, data volume and modelling hours. You receive a range as a non-binding estimate, not a quote. The workflow and equipment are described in Chapter 13.

How the calculation works

m² per scan position = guide value of the building type ÷ level-of-detail factor
Area positions posF = ⌈floor area · levels ÷ m² per scan⌉
Additional positions = staircases · landings · 2 + (vessels + equipment) · levels · scans per equipment item
Positions = round(posF · f_min or f_max) + additional positions

Scans per day and team = ⌊9 h · 60 ÷ (min per scan + relocation/10)⌋
Days on site = ⌈positions ÷ scans per day ÷ teams · 2⌉ ÷ 2 + 0.5
Overnight stays per person = ⌈days⌉ + 1
Registration [h] = 2 h + positions ÷ 9.5
Raw data [GB] = positions · GB per scan (with color × 1.5)

Days are rounded up to half days, plus a flat half day. Relocation and set-up: 2 min per 10 scans.

Modeling

1. Quantities: detected from the documents, entered manually or suggested from the floor area (guide values per 100 m² gross floor area and building type, e.g. industrial: 4 lines, 60 m pipe, 12 valves per 100 m²). Without a pipe length, 15 m per line is assumed; default share up to DN 50 is 40 %.
2. Steel structure from area A and grid r (default 6 m): columns ⌈1.3·A/r²⌉, beams ⌈2.6·A/r²⌉, railings 4·√A.
3. Software for pipe recognition: The piping share (pipe and valves, without instruments) is applied with a factor of 0.5; with a factor of 1 there is no deduction.
4. Allowances on the modelling: checking, clean-up, handover 10 %; coordination and revision 75 % (selectable); plus isometrics per line.

Example with the default values

Evaluate documents (with customer account)

PDF (text of the first 60 pages, optional text recognition for up to 8 pages), photos, ZIP and PCF are read in the browser. The estimator recognizes drawing types via keywords (German, English, Dutch), sheet format and scale, line, equipment and instrument tags, as well as nozzle counts from nozzle lists. Lines = number of isometrics, otherwise number of recognized line numbers. Recognized values are marked and remain editable.

Limits

• Not included: travel, barriers, hazardous areas, access equipment, surveying of control points.
• For more than 15 days on site, the estimator recommends sections or a second team.
• If nozzle counts are missing, the modelling time is too low – the estimator points this out.

Scan estimator ›3D laser scanning ›

Basis: project experience of A. Seitz Ingenieur GmbH; scan times of the “fast” levels according to publicly available manufacturer data for a common phase-based scanner

Catalog from manufacturer data

The tool read valve catalogs as PDF and prepared a Plant 3D catalog with uniform base bodies from them. Since 13 Oct 2026, the page leads to the ASEING Catalog Builder. The recognition rules and base bodies are described here as a method.

How recognition works

• The text layer of PDF files is read (also in ZIP), at most 150 pages per file. Pages with fewer than 40 characters are treated as “without text”.
• Type per page: Keywords (German and English) are counted for each valve type; the type with the most hits applies to the whole page. Priority: 3-way ball valve before ball valve and 3-way valve, 3-way valve before straight-through valve. Pages without hits are skipped.
• Attributes: nominal size DN 4–4000, PN, ASME Class 150–2500, material (material numbers, cast grades, ASTM, plastics), face-to-face length to EN 558 (basic series), connection (flange, wafer, butt weld end, socket weld, thread, clamp, dairy union, aseptic, press) and actuator (lever, handwheel, gearbox, pneumatic, electric, spring).

From P&ID symbol to 3D body: The shape follows the P&ID symbol, the dimensions come from the manufacturer documentation. Triangles become cones from the connections to the centre, the circle becomes a sphere, the dot a small sphere, the line a butterfly disc. Dimensions per size are the face-to-face length (EN 558 basic series or manufacturer table) and connection diameter (flange or pipe outside diameter). Actuators remain separate components and are assigned per nominal size. Reading out the dimension tables is a processing step carried out by ASEING.

Limits

All attributes on a page belong to one valve type; collective catalogs with several types per page must be reworked manually. Scanned PDFs without a text layer are not read.

ASEING Catalog Builder ›Piping catalogs ›

Basis: ASEING catalog standard; face-to-face lengths according to EN 558 (basic series) or manufacturer data

Sources and standards

Status October 2026 · calculation methods of the calculator versions: Piping Spec Calculator 1.47.1 · calculators for pressure drop, thermal expansion, pipe weight, unit converter and plant identification at calculation status 2026-10-17 (verified with 20 test cases and 85 individual checks against an independent reference calculation, test report of the online calculators) · Scan estimator status 12 Oct 2026.