Piping
Hydrostatic test pressure calculator
In short
Under the PED 2014/68/EU and EN 13480-5, the hydrostatic test pressure is PT = max(1.25 × PS × f_test / f; 1.43 × PS). Under ASME B31.3, PT = 1.5 × P × ST / S. The gauge range is picked between 1.5 and 4 PT, as close as possible to 2 PT, from the EN 837-1 ranges.
Calculation
Example calculated with the tool’s default values.
Inputs
- Maximum allowable pressure PS
- 10 bar
- Code
- PED 2014/68/EU · EN 13480-5
- Height from high to low point
- 0 m
Results
- Test pressure (high point)
- 14.30 bar
Worked example
Every value in this section belongs to the example, calculated with the tool’s default values.
Other results of the example
- 1.25 × PS × ratio
- 12.50 bar
- 1.43 × PS
- 14.30 bar
- Gauge range (0 to …)
- 25 bar
- PT read at … of full scale
- 57%
- Indicative value: test pressure and procedure are set by the construction code and the notified body.
Step-by-step calculation
Load term
PT1 = 1.25 × PS × f_essai / f
1.25 × 10.00 × 1.000 = 12.50 bar
Minimum term
PT2 = 1.43 × PS
1.43 × 10.00 = 14.30 bar
Test pressure
PT = max(PT1 ; PT2)
14.30 bar
Gauge range
1.5 PT ≤ E ≤ 4 PT, E proche de 2 PT
21.4 ≤ E ≤ 57.2 → 0 – 25 bar
How to use it
- Enter the maximum allowable pressure PS, in bar.
- Pick the code: PED 2014/68/EU · EN 13480-5, or ASME B31.3.
- If the design temperature is not ambient, enter the stress ratio f_test / f_design (ST / S in B31.3); empty = 1.
- Enter the height from the high point to the low point of the line.
- Read the test pressure at the high point.
Frequently asked questions
What is the hydrostatic test pressure formula?
Under the PED 2014/68/EU (annex I § 7.4) and EN 13480-5 (§ 9.3.2), the test pressure is the larger of two values: PT1 = 1.25 × PS × f_test / f and PT2 = 1.43 × PS. The ratio f_test / f corrects for the design temperature; it is 1 for a design at ambient temperature.
What is the hydrostatic test pressure for a 10 bar line?
With PS = 10 bar under the PED, at ambient temperature: PT1 = 1.25 × 10.00 × 1.000 = 12.50 bar and PT2 = 1.43 × 10.00 = 14.30 bar. The test pressure is therefore 14.30 bar. The gauge must cover 21.4 to 57.2 bar: 0 – 25 bar range, where PT reads at 57.2 % of full scale.
What is the hydrostatic test pressure under ASME B31.3?
ASME B31.3 § 345.4.2 gives PT = 1.5 × P × ST / S, with the ST / S ratio capped at 6.5. The pressure is held for at least 10 min, then the joints are examined at no less than P (§ 345.2.2(a)). If PT would exceed yield at test temperature, B31.3 allows reducing it (§ 345.4.2(c)).
Does the line height matter?
PT applies at the high point. The low point sees the water head Δp = ρ g h / 10⁵ more, in bar: check that the low components can take it.
Limits
Indicative value: test pressure and procedure are set by the construction code and the notified body. The calculation checks neither the pipe wall thickness nor the components' strength at test pressure.
Sources
- Directive 2014/68/UE (DESP) : Annexe I, § 7.4 (pression d’épreuve hydrostatique : max(1,25 × charge ; 1,43 × PS)) (link)
- EN 13480-5 Tuyauteries industrielles métalliques — Inspection et contrôle : § 9.3.2 (PT = max(1,25 PS f_essai/f ; 1,43 PS))
- Manomètre : ASME BPVC VIII-1 UG-102(b) (échelle ≈ 2 PT, entre 1,5 et 4 PT) ; échelles EN 837-1