5 Year Warranty
542F_With_Drain_Plug_SafetyValve_DN40_Nabic_RedBG_v1-copy.jpg 542F_With_Drain_Plug_SafetyValve_DN40_Nabic_RedBG_v2-copy.jpg 542F_With_Drain_Plug_SafetyValve_DN40_Nabic_RedBG_v3-copy.jpg 542F_With_Drain_Plug_SafetyValve_DN40_Nabic_RedBG_v4-copy.jpg

Fig 542F Safety Relief Valve

5 Year Warranty
Buy Online Price from £440.46 (ex vat)

The NABIC Fig 542F is an extremely versatile flanged valve and although designed primarily for the protection of hot water boilers, its wide range of applications make it an ideal general purpose safety valve.

All wetted parts are manufactured from dezincification resistance materials. Designed and tested to BS EN ISO 4126 -1. 

  • Resilient PTFE seating design
  • Easy inspection and cleaning
  • High discharge capacity
  • WRAS Approved:
    • DN20 to DN25 - 1 bar and above
    • DN32 to DN65 - 0.4 bar and above


Pressure Equipment Directive - PED 2014/68/EU
Product Features +

Medium: Hot water, steam, compressed air and inert gasses, Co2 (to 20°C), ethylene glycol, potable water

Size Range: DN32 - DN80

Pressure: 0.3 - 10.5 bar

Material: Gunmetal

Temperature: -20 to 195°C

Connection: Flanged inlet & screwed outlet

Pipe Connections

Flanged inlet connections. Threaded female outlet connections, Rp (BSP) parallel to BS EN 10226-1 Most flange standards can be accommodated.


All valves are shell and seat tested (to confirm set pressure) before leaving the factory and all valves are supplied pre-set with a tamper proof seal. Pressure Test Certificate and Letters of Conformity available on request.

Product Extras

  • Available with Viton seat design
  • Padlock available
  • Pressure setting locked and sealed
  • Drain plug fitted on sizes DN40 and above allows fitting of a pressure gauge


Ref No Name of Part Material
1 Thrust Washer Brass, BS EN 12164 CW609N
2 Grubscrew Steel
3 Test Lever Brass, BS EN 1982 CC754S
4 Spring Chrome Vandium Alloy Steel, BS 2803 735 A50 HS (Stainless Steel, BS 2056 302S26 Opt)
5 Label Yellow kapton
6 Spring Cover Bronze, BS EN 1982 CC491K
7 Piston Brass, BS EN 12164 CW609N
8 Diaphragm Silicon Rubber
9 Seat Seal Holder Bronze, BS EN 1982 CC491K / Brass BS EN 12164 CW602N (DZR)
10 Seat Seal PTFE (Viton Opt)
11 Starlock Washer Stainless Steel
12 Body Bronze, BS EN 1982 CC491K
13 Lever Pin Steel
14 Lead Seal (Not shown) Lead
15 Adjusting Screw Brass, BS EN 12164 CW609N
16 Spring Plate Brass, BS EN 12164 CW609N
17 Spindle Brass, BS EN 12164 CW721R
18 Seat Seal Retaining Plate Bronze, BS EN 1982 CC491K / Brass BS EN 12164 CW602N (DZR)
19 O-Ring Viton

Dimensional Drawing

NABIC Fig 542F

Dimensions & Weights

Inlet Rp BSP
32 Flanged 1 1/4" 46 60 180 3.00
40 Flanged 1 1/2" 54 64 225 4.40
50 Flanged 2" 64 73 263 7.15
65 Flanged 2 1/2" 76 83 303 10.00
80 Flanged 3" 90 96 366 16.41


Downloads +
Discharge Capabilities +
Buy Online +

Fig 542F Safety Relief Valve

Due to difficult market conditions our delivery time is currently four working days from placing your order, although we will endeavour to deliver prior if possible.

  • Customers can only order up to 5 of any one product line. For larger orders please call us on 01462 443 278
  • Please note: if ordering a stock product with a longer lead time product (e.g. 7 to 10 days or 3 to 4 weeks) they will be sent as a combined shipment when ready, unless purchased as separate orders.
  • Online ordering is only available in the UK and Northern Ireland

View Delivery, Returns & Refund Details

Part Number Size Ex Vat Stock Status More
DN32 £ 440.46 7-10 Days +
1.1/4" Flanged Inlet x 1.1/4" BSPP Female Outlet to BS21 - PTFE to Metal Seat
DN40 £ 587.14 7-10 Days +
1.1/2" Flanged Inlet x 1.1/2" BSPP Female Outlet to BS21 - PTFE to Metal Seat
DN50 £ 760.14 7-10 Days +
2" Flanged Inlet x 2" BSPP Female Outlet to BS21 - PTFE to Metal Seat
DN65 £ 1,051.90 7-10 Days +
1.1/2" Flanged Inlet x 2.1/2" BSPP Female Outlet to BS21 - PTFE to Metal Seat
DN80 £ 1,471.14 7-10 Days +
3" Flanged Inlet x 3" BSPP Female Outlet to BS21 - PTFE to Metal Seat

Set Required Pressure

Please type your required set pressure from 0.3 to 10.5. Pressure settings can be in 0.1 increments.
Please check set pressure charts on Discharge Capabilities section.

Test Certificates are included free of charge for this product, and available to download once you have received your serial number.

Price £440.46

You must select a value for all options provided.


What our customers say

We had an existing NABIC Fig. 500 safety valve installed in our steam boiler factory which needed replacing. The valve had started to leak due to its old age.

I had no hesitation in purchasing another as it’s been a great product. I was very happy with the service of the website, as well as the prices. The fact the valves come with the necessary certifications is also great.

Wayne Barnes- Engineering Co-ordinator, Newlywed Foods

Sign up to get the latest product news and offers direct from NABIC