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Full Analysis of Shell Test Requirements for Industrial Valves Under Various Standards

July 3, 2026

Ⅰ Detailed Requirements of Global Standards for Valve Shell Test

1. ASME B16.34-2025

It is a comprehensive valve design standard covering flanged, threaded and welded end valves. Chapter 7 Pressure Test specifies shell test rules:

① Shell test pressure: 1.5 times pressure rating at 38°C;

② Test medium: Water with corrosion inhibitor is preferred; kerosene or other fluids with viscosity no higher than water are acceptable;

③ Maximum medium temperature: Shall not exceed 50°C (125°F);

④ The standard specifies minimum holding duration for shell test, with no limit on chloride ion content.

2. API 598-2023

Specialized standard for valve inspection and testing, applicable to gate, globe, check, ball, butterfly valves. Detailed shell test provisions are as follows:

① Optional test media: Air, nitrogen, inert gas, kerosene, water or media with viscosity no higher than water. Test water can be mixed with water-soluble oil and corrosion inhibitor; wetting agent or antifreeze (ethylene glycol) shall be added if specified by the buyer;

② Updated stainless steel control: Chloride ion content of test water for austenitic stainless steel valves shall not exceed 50 ppm (revised from previous 100 ppm); manufacturers shall provide chloride test certificates;

③ Hydrostatic shell test pressure: In accordance with ASME B16.34, 1.5 times rated pressure at 38°C; Class A butterfly valves under API 609 adopt 1.5 times Cold Working Pressure (CWP);

> Supplementary note: CWP (Cold Working Pressure) refers to the maximum allowable working pressure of valves under normal temperature (≤38°C / 100°F). It is an actual value determined by manufacturers based on product design, material and wall thickness;

④ Optional high-pressure pneumatic shell test: Only carried out when specified in purchase order, performed after hydrostatic shell test with adequate safety protection. Test pressure shall be 110% of maximum allowable pressure at 38°C, with zero visible leakage allowed during the whole test;

⑤ Minimum shell test holding duration (added duration for DN>600 valves):

3. ISO 5208-2015 International Standard for Valve Pressure Testing

① Test medium: Water (with corrosion inhibitor), kerosene, liquid with viscosity no higher than water, air or other applicable gas;

② Medium temperature range: 5°C ~ 40°C;

③ Chloride ion content of test water for austenitic stainless steel valves ≤100 ppm;

④ Test classification: Hydrostatic shell test and pneumatic shell test are specified separately; pneumatic test is optional. Hydrostatic test pressure = 1.5 × CWP; pneumatic test pressure = 1.1 × CWP;

⑤ Mandatory test sequence: If pneumatic shell test is required, liquid shell test must be completed first to verify valve pressure-bearing capacity;

⑥ Minimum shell test holding duration:

4. MSS SP-61-2019 (Manufacturers Standardization Society Standard)

Full name: Pressure Testing of Valves, applicable to on-off valves working under full open / full close conditions; control valves shall refer to ISA-75.19.01 and FCI 70-2;

① Test medium: Air, inert gas, water (with corrosion inhibitor), kerosene or fluid with viscosity no higher than water;

② Maximum medium temperature: ≤52°C (125°F);

③ Mandatory rule: Shell test must be performed before valve painting;

④ Test pressure: No less than 1.5 times rated pressure at 38°C(100°F);

⑤ The standard defines minimum holding duration for valves of all sizes.

5. EN 12266-2012 European Valve Testing Standard

Its general framework is basically consistent with ISO 5208, with additional EU-specific requirements:

① Two mandatory shell tests: Shell Strength Test (P10) and Shell Tightness Test (P11);

② Hydrostatic test medium is limited to liquid; gas medium is only acceptable with mutual written agreement between purchaser and manufacturer;

③ Test pressure: At least 1.5 times PS_RT (Room Temperature Allowable Pressure);

> Supplementary note: PS_RT is a European exclusive term, representing maximum allowable working pressure of valves at 20°C, which can be checked in EN 1092-1 and EN 12516; it differs from American CWP in definition;

⑤ Uniform minimum holding duration is specified for all valve sizes for shell test.

6. ISA 75.19.01-2013 (Full Name: ANSI/ISA-75.19.01) Special Hydrostatic Test Standard for Control Valves

Applicable to control valves whose body, bonnet and flange are made of carbon steel, low alloy steel, high alloy stainless steel, nickel-based alloy, cast iron and ductile iron; complementary to MSS SP-61 for on-off valves;

① Test medium: Water (with corrosion inhibitor) or liquid with viscosity no higher than water;

② Shell test pressure: In accordance with ASME B16.34, 1.5 times rated pressure at 38°C;

③ Holding duration of shell test is differentiated by valve size and pressure class.

7. IEC 60534-4 Standard for Inspection & Routine Testing of Process Control Valves

Applicable to pneumatic control valves with pressure class no higher than Class 2500, the core basis for factory quality verification of control valves;

The 2021 version cancels unified specified shell test pressure and holding duration, requiring reference to corresponding valve design standards (ASME, EN, etc.) for implementation.

8. BS 6364 UK Standard for Cryogenic Valves (-50℃ ~ -196℃)

Designed for LNG, liquid nitrogen and other cryogenic working conditions, specifying extended bonnet structure, stem angle, cryogenic material selection, prototype test and production test. It focuses on cryogenic performance verification, while basic pressure test parameters refer to EN 12266-1 / API 598;

① Chloride ion content of test water ≤30 ppm;

② Test sequence: Shell tightness test shall be carried out after shell strength test;

③ Holding duration is specified by BS 5146 (now replaced by BS 6755 and EN 12266-1);

④ Minimum shell test duration standard:

9. Corresponding Relationship Between Chinese National Standards and International Standards

① GB/T 26480-2011: Corresponding to API 598-2009

② GB/T 13927-2022: Corresponding to ISO 5208-2015

③ GB/T 17213.4-2015: Corresponding to IEC 60534-4:2006

④ GB/T 4213-2024 Domestic Specification for Pneumatic Control Valves:

It does not adopt the holding duration specified in GB/T 17213.4, but formulates stricter independent test duration (2~15 minutes) linked to pressure class. The shell test holding duration of valves inspected under this standard is far longer than that required by IEC 60534-4.

Ⅱ Comparison Table of Shell Test Pressure for All Standards

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Ⅲ Comparison Table of Minimum Shell Test Holding Duration (Unit: Seconds)