Yoshitake AF-5S and AF-5 are full bore safety relief valves with increased safety. These compact and lightweight valves are about half the size of previous full bore type safety valves. The AF-5S is constructed entirely of stainless steel, offering high corrosion resistance and durability. Both models feature a lift lever mechanism that allows manual discharge inspection at more than 75% of the opening pressure.

Features

• Full bore safety valve with increased safety. Compact and lightweight (about half size of the previous full bore type safety valve).
• A material of excellent quality is used for the trim parts. High performance is maintained by precision processing and heat treatment.
• Corrosion-free due to corrosion-resistant material (the AF-5S is all stainless made, offering high corrosion resistance and durability).
• Due to lift lever mechanism a discharge inspection can be manually performed at more than 75% of the opening pressure.

Specifications

Model	AF-5	AF-5S
Structure	Open type with a lever	Open type with a lever
Application	Steam; Air, Other non-dangerous fluids	Steam, Air, Other non-dangerous fluids
Working pressure	0.1-2.0 MPa (Steam) / 0.1-1.0 MPa (Air)	0.1-1.0 MPa
Maximum temperature	220°C	220°C
Material (Spring case)	Bronze	Stainless steel
Material (Valve, valve seat)	Stainless steel	Stainless steel
Connection	Inlet: JIS R screwed Outlet: JIS Rc screwed	Inlet: JIS R screwed Outlet: JIS Rc screwed

Dimensions and Weights

AF-5

Nominal size	Inlet diameter × Throat diameter × Outlet diameter (di × dt × do)	Valve seat diameter (d)	Flow area (dt² π/4)	Lift e (mm)	Dimension L (mm)	Dimension H1 (mm)	Dimension H (mm)	Plug	Weight (kg)
20A	R 1 × 15 × Rc 1	18	176.6	3.3	38	61	136 (151)	R1/8	1.3 (1.5)
25A	R 1-1/4 × 19 × Rc 1-1/4	22	283.3	4.4	45	70	157 (182)	R1/8	1.9 (2.1)
32A	R 1-1/2 × 24 × Rc 1-1/2	28	452.1	5.5	52	80	183 (202)	R1/8	2.7 (3.0)
40A	R 2 × 30 × Rc 2	35	706.5	6.8	65	98	216 (252)	R1/4	5.1 (6.0)

INFO

• The nominal size and the connection size are different.
• The values in parentheses are the values for working pressure 1.6 MPa-2.0 MPa.

AF-5S

Nominal size	Inlet diameter × Throat diameter × Outlet diameter (di × dt × do)	Valve seat diameter (d)	Flow area (dt² π/4)	Lift e (mm)	Dimension L (mm)	Dimension H1 (mm)	Dimension H (mm)	Plug	Weight (kg)
20A	R 1 × 15 × Rc 1	18	176.6	3.3	40	62	163	R1/8	1.65
25A	R 1-1/4 × 19 × Rc 1-1/4	22	283.3	4.4	47	70	190	R1/8	2.35
32A	R 1-1/2 × 24 × Rc 1-1/2	28	452.1	5.5	52	79	208	R1/8	2.90
40A	R 2 × 30 × Rc 2	35	706.5	6.8	65	98	248	R1/4	5.30

INFO

• The nominal size and the connection size are different.

At the Time of Ordering

TIP

When ordering, please inform set pressure and application. (If the application is steam, please also specify the usage either pressure vessel structure or boiler structure.)

Certified Capacity Table for AF-5, 5S

• For steam (saturation temperature) <Pressure vessel structure standard> (kg/h)

Pressure MPa / Nominal size	0.1	0.2	0.3	0.4	0.5	0.6	0.7	0.8	0.9	1.0
20A	159	231	310	390	468	545	621	697	773	849
25A	255	370	498	627	751	875	997	1118	1240	1362

• For air (20˚C) <Pressure vessel structure standard> (kg/h)

Pressure MPa / Nominal size	0.1	0.2	0.3	0.4	0.5	0.6	0.7	0.8	0.9	1.0
20A	257	374	502	630	759	887	1015	1143	1272	1400
25A	413	600	806	1011	1217	1423	1629	1835	2040	2246

INFO

Please refer to -12 for the calculation procedure for nominal size selection. Note: Some table rows and columns have been omitted for brevity due to source text limitations.