Relief Valve for Distribution Manifolds | Specifications & Standards

Product Specifications

Technical details and manufacturing context for Relief Valve

Definition

A relief valve is a safety component designed for integration into a distribution manifold or block system. Its primary function is to protect the fluid distribution network and connected equipment from damage caused by excessive pressure buildup. When system pressure reaches a predetermined set point, the valve opens to discharge a controlled amount of fluid (liquid or gas) to the atmosphere or a return line, thereby reducing pressure to a safe operating level before resealing. This valve is typically an optional addition, but it is critical for systems where pressure fluctuations can occur. The valve operates on a force-balance principle: a spring or other actuating element applies a closing force to a sealing element (disc, poppet, or diaphragm). When the upward force from system pressure on the sealing area exceeds the spring force, the valve lifts off its seat, creating an opening for fluid to escape. Once pressure drops below the set point, the spring force reseats the valve, stopping the flow. The valve is available in nominal diameters from DN15 to DN50, with a set pressure range of 0.1 to 1.6 MPa, and an accuracy of ±5% of set pressure. Operating temperature ranges from -40°C to 120°C, limited by seat material. Body materials include stainless steel (304/316) and brass, with PTFE seat material for chemical resistance. Connection types include flanged, and leakage rate is ≤0.01 mL/min at set pressure. Flow capacity at 10% overpressure is 0.5 to 10 m³/h, and weight ranges from 2.5 to 15 kg depending on size. These values are reference ranges; verify model-specific specifications with the manufacturer. The valve complies with standards such as ISO 5208, ISO 4126-1, ASTM A351, ASTM D4894, and ISO 7005, but these are procurement references, not certification guarantees.

Working Principle

The relief valve operates on a force-balance mechanism. A spring applies a downward closing force on a sealing element (disc, poppet, or diaphragm). System pressure acts on the sealing area, generating an upward force. When this upward force exceeds the spring force, the valve lifts off its seat, allowing fluid to flow out. This reduces system pressure until the upward force drops below the spring force, at which point the spring reseats the valve, stopping flow. The set pressure is adjustable within the specified range.

Common Materials

Stainless Steel (Body/Spring), Elastomer (Seal), Brass

Technical Parameters

Parameter	Typical range	Notes & selection driver
Nominal Diameter	DN15–DN50 mm	Matches pipeline size
Set Pressure Range	0.1–1.6 MPa	Adjustable within rangeISO 4126-1
Accuracy	±5 %	Of set pressureISO 4126-1
Operating Temperature	-40–120 °C	Seat material limit
Body Material	304/316	Stainless steelASTM A351
Seat Material	PTFE	Chemical resistanceASTM D4894
Connection Type	Flanged	Other types availableISO 7005
Leakage Rate	≤0.01 mL/min	At set pressureISO 5208
Weight	2.5–15 kg	Depends on size
Flow Capacity	0.5–10 m³/h	At 10% overpressureISO 4126-1

Ranges are indicative industry figures for RFQ preparation, not a supplier commitment. Confirm every value and standard with the legal manufacturer before ordering.

Components / BOM

Valve Body
Houses internal components and provides inlet/outlet connections to the manifold.

Material: Stainless Steel or Brass
Spring Part
Provides the adjustable closing force that determines the set pressure.

Material: Stainless Steel
Poppet/Disc Part
The moving sealing element that lifts off the seat to allow flow when pressure is exceeded.

Material: Stainless Steel
Seal (O-ring/Gasket) Part
Ensures a leak-tight seal between the poppet/disc and the valve seat when closed.

Material: FKM (Viton) or NBR (Nitrile) Elastomer
Adjustment Screw/Cap Part
Allows for calibration and adjustment of the spring tension to set the relief pressure.

Material: Stainless Steel or Brass

Application & selection

Application Fit & Sizing Matrix

Operational Limits

pressure:	Up to 6000 psi (414 bar)
other spec:	Flow capacity: 10-500 GPM (38-1893 L/min), Slurry concentration: ≤5% solids by weight
temperature:	-20°C to 150°C

Media Compatibility

✓ Hydraulic oil ✓ Process water ✓ Compressed air

Unsuitable: Highly corrosive acids (e.g., hydrochloric acid, sulfuric acid)

Sizing Data Required

Required relief pressure (set point)
Maximum flow rate during relief event
Fluid properties (density, viscosity, compressibility)

Risk, maintenance & compliance

Reliability & Engineering Risk Analysis

Failure Mode & Root Cause

Sticking or Failure to Open

Cause: Corrosion, fouling, or accumulation of debris on the valve seat or moving parts, preventing proper operation when pressure exceeds setpoint.

Leakage or Failure to Reseat

Cause: Wear or damage to the valve seat or disc from erosion, corrosion, or improper installation, causing the valve to leak after activation or not fully close.

Maintenance Indicators

Audible hissing or continuous leakage from the valve discharge, indicating it's not reseating properly.
Visible corrosion, physical damage, or signs of tampering on the valve body or adjustment mechanism.

Engineering Tips

Implement a regular testing and inspection schedule per ASME standards to verify set pressure and reseating performance, using calibrated equipment.
Ensure proper installation with adequate support and alignment, and protect the valve from environmental contaminants and corrosive atmospheres.

Indicative industry ranges for design and RFQ preparation. Confirm the exact figures and applicable standard with the manufacturer before specifying.

Compliance & Manufacturing Standards

Applicable Standards

ISO 4126-1: Safety devices for protection against excessive pressure - Safety valves ASME/ANSI B16.34: Valves - Flanged, Threaded, and Welding End DIN EN ISO 4126-1: Sicherheitseinrichtungen gegen unzulässigen Überdruck - Sicherheitsventile

Quoted from the published standard.

Manufacturing Precision

Set Pressure: +/-3% of specified pressure
Seat Leakage: Zero detectable leakage at 90% of set pressure

Quality Inspection

Hydrostatic Shell Test: 1.5 times maximum allowable working pressure
Set Pressure and Pop Test: Functional verification at specified operating conditions

Procurement Evaluation Criteria

A practical evidence checklist for RFQ preparation and supplier evaluation.

Technical documentation

Request current drawings, revision history, and a signed specification sheet.

Manufacturing capability

Verify equipment lists, process limits, capacity, and representative production evidence.

Inspection readiness

Confirm test methods, calibrated equipment, sampling plans, and traceable reports.

Supplier transparency

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Compare the published product scope and source details, then include your specifications and quantity in an enquiry.

Manufacturers of Relief Valve

12 companies list this product among what they make. Company figures are quoted from each company's own website; every card states where the relationship came from.

China Sanitary Valve

Zhejiang, CN

Founded 200251~100 staff5,000-10,000 square meters

ISO9001 ASME CE Test Report

Also makes: Sanitary Pressure Relief Valve, Sanitary Centrifugal Pump, Dairy Flow Control Diaphragm Valve and 9 more

Listed on the company's own website · profile compiled by CNFX from public sources

Listed there as: “Sanitary Pressure Relief Valves”
View source page ↗ chinasanitaryvalve.com · recorded 2026-08-22

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Dongying Lake Petroleum Technology CO., Ltd

Shandong, CN

ISO GOST

Also makes: Desanders/Desilters, Hydraulic Power Unit, Pulsation Dampener and 9 more

Listed on the company's own website · profile compiled by CNFX from public sources

Listed there as: “Relief Valve”
View source page ↗ lakepetro.com · recorded 2026-08-22

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Hydraflu Hydraulic Co.

Shanghai, CN

Also makes: Directional Control Valve, Pressure Reducing Valve, Pressure Control Valve and 9 more

Listed on the company's own website · profile compiled by CNFX from public sources

Listed there as: “Relief Valve”
View source page ↗ hydraflu.com · recorded 2026-08-22

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Poocca Hydraulics (Shenzhen) Co., Ltd.

Shenzhen, Guangdong, CN

Founded 200680 staff8,000 square meters

GB/T19001-2016/ISO9001:2015

Also makes: Pressure Relief Valve, Hydraulic Piston, Hydraulic Pump and 8 more

Listed on the company's own website · profile compiled by CNFX from public sources

Listed there as: “Hydraulic Pressure Relief Valve”
View source page ↗ pooccahydraulic.com · recorded 2026-08-22

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Wenzhou Deyi Machinery

Wenzhou, Zhejiang, CN

Also makes: Sanitary Centrifugal Pump, Dairy Flow Control Diaphragm Valve, Safety Relief Valve and 9 more

Listed on the company's own website · profile compiled by CNFX from public sources

Listed there as: “Sanitary Safety Relief Valve”
View source page ↗ technologyvalve.com · recorded 2026-08-22

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Anhui Leading Forklift Parts Co., Ltd.

Shenyang, Liaoning, CN

Also makes: Engine Assembly, Mast assembly, Hydraulic Steering Cylinder and 9 more

Listed on the company's own website · profile compiled by CNFX from public sources

Listed there as: “Relief Valve”
View source page ↗ leadingforkliftparts.com · recorded 2026-09-16

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Bestec

Shijiazhuang, Hebei, CN

Also makes: Gate Valve, Agricultural Machinery, Pressure Relief Valve and 8 more

Listed on the company's own website · profile compiled by CNFX from public sources

Listed there as: “Pressure Relief Valve”
View source page ↗ bestec.cn · recorded 2026-09-07

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Botou Yaxing Fluid Equipment Co.,Ltd.

Cangzhou, Hebei, CN

Also makes: Gate Valve, Pressure Reducing Valve, Pressure Relief Valve and 7 more

Listed on the company's own website · profile compiled by CNFX from public sources

Listed there as: “Pressure relief valve”
View source page ↗ civalves.com · recorded 2026-10-11

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CHINA YOY VALVE GROUP

Wenzhou, Zhejiang, CN

Also makes: Metal Tank Pressure Relief Valve Assembly, Safety Relief Valve, Regulating Valve (Actuator) and 2 more

Listed on the company's own website · profile compiled by CNFX from public sources

Listed there as: “SAFETY RELIEF VALVE”
View source page ↗ yoyvalves.com · recorded 2026-09-08

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Chinadrip Irrigation Equipment (Xiamen) Co., Ltd.

Xiamen, Fujian, CN

Also makes: Pressure Reducing Valve, Pressure Regulator, Solenoid Valve and 8 more

Listed on the company's own website · profile compiled by CNFX from public sources

Listed there as: “Vacuum Relief Valve”
View source page ↗ chinadrip.com · recorded 2026-08-30

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Dongturbo Electric Company Ltd

Chengdu, Sichuan, CN

Also makes: Battery System, Energy Storage/Transfer Element (for active systems), Power Plant and 5 more

Listed on the company's own website · profile compiled by CNFX from public sources

Listed there as: “Adjustable Pressure Relief Valve”
View source page ↗ dongturbo.com · recorded 2026-08-27

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Dongying Giayoung Precision Metal Co., Ltd.

Dongying, Shandong, CN

Also makes: Bearing/Housing, Hub/Centerbody, Butterfly Valve

Listed on the company's own website · profile compiled by CNFX from public sources

Listed there as: “Relief Valve”
View source page ↗ cast-china.com · recorded 2026-10-11

View profile Send enquiry

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Frequently Asked Questions

What is the purpose of a relief valve in a distribution manifold?

It protects the manifold and connected equipment from damage due to excessive pressure by automatically releasing fluid when pressure exceeds a preset limit.

What are the available nominal diameters and set pressure ranges?

Nominal diameters range from DN15 to DN50, and set pressure is adjustable from 0.1 to 1.6 MPa. These are reference ranges; confirm exact values for your model.

What materials are used for the valve body and seat?

Body materials include stainless steel (304/316) and brass. The seat is made of PTFE for chemical resistance. Verify material suitability for your application.

Which standards apply to this relief valve?

Relevant standards include ISO 5208 for leakage, ISO 4126-1 for pressure relief devices, ASTM A351 for body material, ASTM D4894 for PTFE, and ISO 7005 for flanged connections. These are references for verification, not certification.

Relief Valve

Product Specifications

Application & selection

Application Fit & Sizing Matrix

Risk, maintenance & compliance

Reliability & Engineering Risk Analysis

Compliance & Manufacturing Standards

Procurement Evaluation Criteria

Manufacturers of Relief Valve

Request manufacturing insight for Relief Valve

Frequently Asked Questions

What is the purpose of a relief valve in a distribution manifold?

What are the available nominal diameters and set pressure ranges?

What materials are used for the valve body and seat?

Which standards apply to this relief valve?

Related equipment

Applied To / Applications

Industrial Ecosystem & Supply Chain Structure

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