5 Year Warranty
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Fig 542L Pressure Relief Valve

5 Year Warranty
Buy Online Price from £177.34 (ex vat)

The NABIC Fig 542L has been designed primarily for use where high tightness is required on the discharge side, having a sealed spring cover to prevent the possibility of back pressure leakage through the top of the valve.

The lift is progressively proportional to flow. All wetted parts are manufactured from dezincification resistance materials. Designed and tested to BS EN ISO 4126 -1.

  • High discharge capacity.
  • Pressure tight on discharge side
  • Suitable for liquids and inert gases
Pressure Equipment Directive - PED 2014/68/EU
Product Features +

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

Size Range: DN15 - DN80

Pressure: 0.3 - 10.5 bar

Material: Gunmetal

Temperature: -20 to 195°C

Connection: Screwed inlet & outlet

Pipe Connections

Screwed female inlet and outlet connections. inlet and outlet connections are of equal size. Threaded connections are Rp BSP parallel to BS EN 10226-1 NPT connections are available upon request.


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
  • 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 Leak Proof Dome Bronze, BS EN 1982 CC491K
2 Locknut Brass, BS EN 12164 CW609N
3 Dome 'O' Ring Viton
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 Cover Seal Viton
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 Adjusting Screw Brass, BS EN 12164 CW609N
14 Spring Plate Brass, BS EN 12164 CW609N
15 Spindle Brass, BS EN 12164 CW721R
16 Seat Seal Retaining Plate Bronze, BS EN 1982 CC491K /
Brass BS EN 12164 CW602N (DZR)
17 O-Ring Viton

Dimensional Drawing

Dimensions & Weights

Inlet & Outlet
15 1/2" 30 23 113 0.50
20 3/4" 34 23 118 0.70
25 1" 39 27 132 0.93
32 1 1/4" 46 33 158 1.50
40 1 1/2" 54 38 200 2.41
50 2" 64 46 239 4.32
65 2 1/2" 76 55 285 8.24
80 3" 90 65 345 12.60


Downloads +
Discharge Capabilities +
Buy Online +

Fig 542L Pressure Relief Valve

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

  • Customers can order up to 12 of any one product line. For larger orders please call us on 01462 443 278
  • Order over £400 for Free Delivery
  • Due to the COVID-19 pandemic orders may take a little longer to deliver than usual.
  • Online ordering is only available in the UK and Northern Ireland

View Delivery, Returns & Refunds Details


Part Number Size Ex Vat Stock Status More
DN15 £ 177.34 4 Weeks +
1/2" BSPP Female Inlet and Outlet to BS21 - PTFE to Metal Seat
DN20 £ 203.59 4 Weeks +
3/4" BSPP Female Inlet and Outlet to BS21- PTFE to Metal Seat
DN25 £ 269.30 4 Weeks +
1" BSPP Female Inlet and Outlet to BS21 - PTFE to Metal Seat
DN32 £ 370.93 4 Weeks +
1.1/4" BSPP Female Inlet and Outlet to BS21 - PTFE to Metal Seat
DN40 £ 496.91 4 Weeks +
1.1/2" BSPP Female Inlet and Outlet to BS21 - PTFE to Metal Seat
DN50 £ 627.04 4 Weeks +
2" BSPP Female Inlet and Outlet to BS21 - PTFE to Metal Seat
DN65 £ 880.58 4 Weeks +
2.1/2" BSPP Female Inlet and Outlet to BS21 - PTFE to Metal Seat
DN80 £ 1,260.66 4 Weeks +
3" BSPP Female Inlet and 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 £177.34

You must select a value for all options provided.


What our customers say

The reason I went to NABIC was because we have to meet certain water regulations. After a chat with Northumbrian Water, they suggested looking into NABIC products as they are WRAS approved and suitable to use on all potable water applications.

I went direct and bought 4 pipe interrupters with next day delivery, which have been installed in our on-site laboratory. My user experience was great and I liked the fact that site has all the necessary specifications and prices easily to hand.

Peter Bauckham - Managing Director, Argos Inspection

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