Pressure Relief Valve Codes and Standards List

Pressure Safety and Relief Valves (PSV) are totally directed by codes and regulations. The four most important codes and standards for PSVs (safety valve standards) are ASME (USA), API (USA), ISO (international) and PED (Europe).

ASME and API Safety Valve Standards for PRV.

We will try simplifies the main objective of the API and ASME play on pressure relief valves, and how the code and standards are envisioned to be used:

1. API 526 provides basic design requirement for spring loaded and piloted operated PSVs:
   1. Orifice designation and area.
   2. Valve size and pressure rating, inlet and outlet.
   3. Materials.
   4. Pressure-temperature limits.
   5. Centre-to-face dimensions, inlet and outlet.
2. API 520 provides detailed sizing procedure and methods based on steady state flow:
   1. Determine the required relief loads.
   2. Select preliminary valve sizes.
3. ASME BPVC manages testing, reparation and certification of safety relief valves.

Most manufacturers have approvals from ASME and PED (as they considered as laws). When installing, select settings or sizing a safety valve, you need to be in accordance with these codes.

The leading standards and acclaimed practises are API 520 (USA) part 1 and part 2, EN4126 (Europe) and ISO 4126 and its 10 parts.

API 520 part 1 & part 2 incorporates details on Sizing, Selection, and Installation of Pressure-relieving Devices. API 520 includes information on correction factors (more conservative) for back pressure and viscosity, therefore is the standards (code) mostly used for pressure relief valve sizing or installation.

USA Standards for Pressure Relief Valve.

API (American Petroleum Institute ).

Europe.

International ISO (International Organization for Standardization).