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5 Year Warranty
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Fig 500FN Pressure Relief Valve

5 Year Warranty
Buy Online Price from £634.62 (ex vat)

The NABIC 500FN safety valve is 316 Stainless Steel construction, designed and tested to BS EN ISO 4126 -1, fitted with resilient PTFE to metal seating design.

To improve flow, the internal surface finish of the body is of a high level by utilising the latest casting techniques.

  • High discharge capacity.
  • Pressure tight on discharge side
  • Corrosion resistant and suitable for difficult liquids or gases
Pressure Equipment Directive - PED 2014/68/EU
Product Features +

Medium: Acids & gases. Please check with Technical Department.

Size Range: DN15 - DN25

Pressure: 0.4 - 11 bar

Material: Stainless Steel

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 (BSP) parallel to BS EN 10226-1.


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

  • Pressure setting locked and sealed


Ref No Name of Part Material
1 Leak Proof Dome Stainless Steel, BS 970 316S11
2 Locknut Stainless Steel, BS 970 316S11
3 Dome 'O' Ring Viton
4 Spring Stainless Steel, BS 2056 302S26
5 Label Yellow kapton
6 Spring Cover Stainless Steel, BS 3146 ANC 4BFC
7 Piston Stainless Steel, BS 970 316S11
8 Cover Seal Viton
9 Seat Seal Holder Stainless Steel, BS 970 316S11
10 Seat Seal PTFE (Viton Opt)
11 Starlock Washer Stainless Steel
12 Body Stainless Steel, BS 3146 ANC 4BFC
13 Adjusting Screw Stainless Steel, BS 970 316S11
14 Spring Plate Stainless Steel, BS 970 316S12
15 Spindle Stainless Steel, BS 970 316S13
16 Seat Seal Retaining Plate Stainless Steel, BS 970 316S14
17 O-Ring Viton


Dimensional Drawing

Dimensions & Weights

15 1/2" 3/4" 33 24 119
20 3/4" 1" 45 60 132
25 1" 1 1/4" 54 64 157


Downloads +
Discharge Capabilities +
Buy Online +

Fig 500FN 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 £ 634.62 5 weeks +
1/2" BSPP Female Inlet x 3/4" BSPP Female Outlet to BS21 - PTFE to Metal Seat
DN20 £ 681.93 5 weeks +
3/4" BSPP Female Inlet x 1" BSPP Female Outlet to BS21 - PTFE to Metal Seat
DN25 £ 845.46 5 weeks +
1" BSPP Female Inlet x 1.1/4" BSPP Female Outlet to BS21 - PTFE to Metal Seat

Set Required Pressure

Please type your required set pressure from 0.4 to 11.0. 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 £634.62

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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