RA Relief Valve

Classification: Relief Valves、Overflow Valves

Max. Working Pressure: 3.4～300bar
DN:5～10mm
Working Temperature: -10℃～+50℃
Body Material: 304 Stainless steel

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Product description

Parameters Table

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Product details：

RA Series Fully Enclosed Safety Relief Valve (1/4″~1″)

Uses
Intended for limiting the pressure of liquid or gas systems, thereby preventing system pressure from exceeding the preset safe value (set pressure). when inlet pressure exceeds the set value, the pressure is released through the outlet.

Features
● Disk seal: soft seal structure, good gas tightness
● Direct acting construction, flexible valve operation
● Wide range of pressure setting, from 3.4 bar to 300 bar
● Casing pressure rating: 400 bar

Operating Principle: When inlet end pressure goes beyond the set pressure, it overcomes the spring force and opens the disk, and the medium at the inlet end is discharged via the relief valve to the outlet end, thereby controlling the inlet end pressure within the set range. The outlet end generally connects a vent, or it will affect pressure relief. When system pressure falls below the re-seating pressure, the disk and the seat close.

Technical Data
● Set pressure repeatability: ±5%
● Min. re-seating pressure: 85%*set pressure
● Casing material: 304 stainless steel
● Disk material: FPM (set pressure: 3.4~150 bar, -25℃~+150℃) EPDM (set pressure: 3.4~150 bar, -45℃~+100℃) PU (set pressure: 45~300 bar, -25℃~+80℃)
● O-ring material: FPM (-25℃~+180℃), EPDM optional (-45℃~+120℃)

Note: RA series relief valves are used in common pressure relief applications to prevent over-pressure, but not used as relief valves defined in pressure vessel design standards.

Ordering Information

Parameters Table：

Table of Technical Data [mm]

DN	Ordering Number	Inlet	Outlet	Set Pressure 3.4~150 bar			Set Pressure 135~300 bar
DN	Ordering Number	Inlet	Outlet	A	B	C	A	B	C
5	R3A-1/4NPTM-1/4NPT-SS	1/4NPT Male Thread	1/4NPT Female Thread	60	37	28	80	36	28
5	R3A-R1/4M-R1/4-SS	R1/4 Male Thread	Rc1/4 Female Thread	60	36	28	80	35	28
7	R4A-R1/2M-R1/2-SS	R1/2 Male Thread	Rc1/2 Female Thread	79	42	39	98	44	35.5
10	R5A-R1M-R1-SS	R1 Male Thread	Rc1 Female Thread	102	62	50	123	57	45.5

Application of Disk and O-ring Materials

Material	Uses
FPM	Good corrosion resistance; applicable to most media; intolerant of ammonia, alcohols and diethyl ether; temperature: -25℃~+150℃
EPDM	Intended for ammonia, vapor, formaldehyde and ethylene glycol; mineral oil intolerant; temperature: -45℃~+100℃
PU	Applicable to air, oils and water，temperature: -25℃～+80℃

Table of R3A/R4A/R5A Spring Selection and Disk Materials

Spring Code	Pressure Setting Range	Disk Material	Valve Series
X	3.4～10bar	FPM or EPDM	R3A/R4A/R5A
A	8～24bar	FPM or EPDM
B	21～50bar	FPM or EPDM
C	45～100bar	FPM or EPDM
D	90～150bar	FPM or EPDM
E	135～220bar	PU
F	185～300bar	PU