Safety Relief Valve

Spring Loaded Steam Safety Relief Valve

Spring Loaded Steam Safety Relief Valve is used in power plant boilers,pressure containers and temperature reducing devices and other facilities.It serves to prevent pressure from exceeding max. allowed value and ensure the safety of the device during working.Steam Safety Valve sizing and selection API 520(ASME secⅧ),designed API 526,test API 527(ASME PTC 25),flange ASME B16.5. This valve’s type include A48C Open Bonnet Plain Lever Safety Valve,A48Y High Temperature and High Pressure With Radiator Safety Valve,High Performance Steam Safety Valve which meets the requirement of ASME secⅠ,High Temperature High Pressure Welded Safety Valve.

Spring Loaded Steam Safety Relief Valve


  • Open Bonnet ,with radiator
  • Safety Valves/pressure safety valves, angle type
  • Low/Full lift safety valve for high temperture and high pressure condition metal to metal seated,with lever,
  • Inlet: Flanged connection ASME,DIN,JIS,BS etc.
  • Outlet: Flanged connection ASME,DIN,JIS,BS etc.


Spring Loaded Steam Safety Relief Valve is applicable as the pressure protecting device in the equipment or pipelines for steam, air,etc., which the working medium is ≤350℃.

Standards Compliance:

Design and Manufacture:API RP 520

Face to Face(end to end):API 526

Test and Inspection:API 527


  1. spring loaded low lift open bonnet safety relief valve with lever(A47)
  2. spring loaded Full lift open bonnet safety relief valve with lever(A48)

In order to offer a quotation,we need specifications as following:

  1. Flange Connection standard
  2. Pressure Rating
  3. Size
  4. Set Pressure
  5. Material for Body&Trim (Material for inside parts).
  6. Medium
  7. Working Temperature

Main property specification

Nominal Pressure PN(Class) 150 300 600
Body strength Ps(Mpa) 3.0 7.5 15
Set pressure Pk(Mpa) 0.1-2 1.6-5 3.2-10
Seal pressure Pm(Mpa) 90%Pk
Reseation pressure Ph(Mpa) ≥90%Pk
Relieving Pressure Pp(Mpa) ≤1.03Pk
Lift height H(mm) ≥1/4 d0
Appropriate temp.
Appropriate Medium Steam

Code of throat diameter

Code Diameter Code Diameter
D 10 L 50
E 13 M 55
F 16 N 60
G 20.5 P 72
H 26 Q 96
J 33 R 115
K 40 T 148

Spring Loaded Steam Safety Relief Valve Materials list

No Name of part Materials
1 Body WCB CF8 CF8M
2 Nozzle 2Cr13/ 304 CF8 CF8M
3 Adjusting Ring 2Cr13/ 304 304 316
4 Disc 2Cr13/ 304 304 316
5 Guide sleeve 2Cr13/ 304 304 316
6 Bonnet WCB CF8 CF8M
7 Spring 50CrVA 50CrVA coated teflon 50CrVA coated teflon
8 Stem 2Cr13 304 316
9 Adjusting bolt 45 2Cr13 2Cr13
10 Cap ZG200-400 ZG200-400 ZG200-400

Sealing surface of material "H" depositing D507, "Y" depositing stellite

Drawing For Example:

Spring Loaded Steam Safety Relief Valve

For more details, please download catalogue for reference or contact with us.

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