FIG. 8340 DOUBLE AIR RELEASE VALVE

Usage for potable & filtered water
Double orifice air valve that combines both large orifice & small orifice functions within one unit.
The large orifice allows air to be expelled from the system during filling of a pipeline and admit air back into the system whenever subatmospheric pressure occurs.
Air is vented from the system until water enters the valve and lifts the float against its seat, ensuring a tight seal.
In the event of sub-atmospheric pressure in the system, the water level drops causing the float to fall from its seat and allow the admission of air.
During normal working of the main the small orifice releases the air which accumulates under pressure. With the main in operation, the float is normally against its seat.
As air enters the chamber body the water level is depressed until a level is reached when the float drops from its seat, which allows air to escape. The consequent rise in water level returns the float to its seat.
25mm (1”) – 200mm (8”) sizes.

Suitable for:

Valve type:

Description

Usage for potable & filtered water
Double orifice air valve that combines both large orifice & small orifice functions within one unit.
The large orifice allows air to be expelled from the system during filling of a pipeline and admit air back into the system whenever subatmospheric pressure occurs.
Air is vented from the system until water enters the valve and lifts the float against its seat, ensuring a tight seal.
In the event of sub-atmospheric pressure in the system, the water level drops causing the float to fall from its seat and allow the admission of air.
During normal working of the main the small orifice releases the air which accumulates under pressure. With the main in operation, the float is normally against its seat.
As air enters the chamber body the water level is depressed until a level is reached when the float drops from its seat, which allows air to escape. The consequent rise in water level returns the float to its seat.
25mm (1”) – 200mm (8”) sizes.

Options

Various flange drillings
Screwed or flanged outlet facility
Viton rubber seat
Metal float options
Surge arrestor
Inflow/Outflow check device
Non-return device
Adjustable throttle device
Bib tap / test point
Isolating valve
25 bar version
40 bar version (on 25mm only)

Technical Specification

PART

PARTS

MATERIAL

STANDARDS

1

Body

GGG50

BS EN 5163:EN-GJS-500-7

2

Cover

GGG50

BS EN 5163:EN-GJS-500-7

3*

Sheild Plate

GGG50

BS EN 5163:EN-GJS-500-7

*(Spun steel on 150 & 200mm)

4

Large Orifice Seat

EPDM

BS EN2428

5

Large Orifice Float

ABS

BS EN ISO 19062-1:2015

6

Small Orifice Float

ABS

BS EN ISO 19062-1:2015

7

Orifice Plug

ABS

BS EN ISO 19062-1:2015

8

Orifice Nut

ABS

BS EN ISO 19062-1:2015

9

Hinge Pin

Stainless Steel

ASTM A276

10

Stop Screw

Stainless Steel

ASTM A276

11

Small Orifice Seal

EPDM

BS EN2428

12

Chamber O-ring

EPDM

BS EN2428

13

Gasket, Orifice Plug

EPDM

BS EN2428

14

Shield Studs & Nuts

Stainless Steel

ASTM A276

15

Cover Bolts & Nuts

Stainless Steel

ASTM A276

16

Chamber Setscrews

Stainless Steel

ASTM A276

17

Chamber

GGG50

BS EN 5163:EN-GJS-500-7

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