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5 Year Warranty
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Fig 500L Pressure Relief Valve

5 Year Warranty
Buy Online Price from £170.91 (ex vat)

The NABIC 500L is 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 - DN65

Pressure: 0.4 - 12.5 bar

Material: Gunmetal

Temperature: -20 to 195°C

Connection: Screwed inlet & outlet

Pipe Connections

Screwed female inlet and outlet connections. outlet connection is one size larger than inlet connection. Threaded connections are Rp 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 DN32 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 Drawings


Dimensions & Weights

15 1/2" 3/4" 33 20 123 0.70
20 3/4" 1" 39 24 136 0.93
25 1" 1 1/4" 45 30 155 1.42
32 1 1/4" 1 1/2" 54 36 201 2.50
40 1 1/2" 2" 64 41 236 4.63
50 2" 2 1/2" 76 47 267 7.00
65 2 1/2" 3" 90 60 330 12.50


Downloads +

BIM Library

Discharge Capabilities +
Buy Online +

Fig 500L Pressure Relief Valve

  • Online ordering is only available in the UK and Northern Ireland
  • 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.

View Delivery, Returns & Refund Details

Part Number Size Ex Vat Stock Status More
DN15 £ 170.91 Limited stock +
1/2" BSPP Female Inlet x 3/4" BSPP Female Outlet to BS21 - PTFE to Metal Seat
DN20 £ 219.10 Limited stock +
3/4" BSPP Female Inlet x 1" BSPP Female Outlet to BS21 - PTFE to Metal Seat
DN25 £ 309.52 Limited stock +
1" BSPP Female Inlet x 1.1/4" BSPP Female Outlet to BS21- PTFE to Metal Seat
DN32 £ 431.15 Limited stock +
1.1/4" BSPP Female Inlet x 1.1/2" BSPP Female Outlet to BS21 - PTFE to Metal Seat
DN40 £ 565.34 Limited stock +
1.1/2" BSPP Female Inlet x 2" BSPP Female Outlet to BS21 - PTFE to Metal Seat
DN50 £ 816.89 Limited stock +
2" BSPP Female Inlet x 2.1/2" BSPP Female Outlet to BS21- PTFE to Metal Seat
DN65 £ 1,113.27 Limited stock +
2.1/2" BSPP Female Inlet x 3" BSPP Female Outlet to BS21 - PTFE to Metal Seat

Set Required Pressure

Please type your required set pressure from 0.4 to 12.5. 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 £170.91

You must select a value for all options provided.


What our customers say

After an insurance recommendation I decided to replace one of our Safety Relief Valves. Working within the pharmaceutical industry, the valve was required for hot water calorifier.

The service on the site was great and I liked the fact that the certifications arrive with the products. We at Bayer have limited access to wholesalers, buying direct from NABIC using a bank card proved to be a much easier transaction.

Chris Green, Bayer

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