Yoshitake AF-4 and AF-4M are open type safety relief valves designed for steam, air, and other non-dangerous fluids. The relief capacity of these valves exceeds that of standard low-lift types.

Features

• Relief capacity exceeds that of a low-lift type.
• Features a lifting lever mechanism; when the pressure reaches 75% or more of the set pressure, relief can be manually checked (AF-4).
• Chinese TS certified products are available.

Specifications

Structure	Open type
Applicable Fluid	Steam, air, other non-dangerous fluids
Working Pressure	0.1 - 1.0 MPa
Applicable Temperature	220℃
Body Material	Ductile cast iron
Spring Chamber Material	Ductile cast iron
Valve & Valve Seat Material	Stainless steel
Connection	JIS 10K FF flanged, JIS 10K RF flanged *1

*1 The inlet for 100A-150A is a JIS 10K RF flange.

Dimensions and Weight

Nominal Size	Inlet × Nozzle × Outlet	Relief Area (mm²)	Lift (mm)	L (mm)	H1 (mm)	HL (mm)	Hx (mm)	Weight (kg)
25A	25×16×40	200.9	3.7	100	100	358	335	12
40A	40×26×65	530.6	6.0	120	120	410	408	21
50A	50×30×75	706.5	6.8	130	130	459	453	27

(Note: Data shown is partial. For full dimensions, refer to the manufacturer's catalog.)

INFO

Connection flange specifications are Inlet: JIS B2239 10K FF or JIS B2239 10K RF, but the inlet flange thickness (T dimension) is larger than the JIS standard value. Outlet is JIS B2239 10K FF.

Ordering Information

When ordering, please specify the working fluid in addition to the set pressure. (For steam, please indicate whether it is for a pressure vessel or a boiler.)

Rated Relief Capacity

(Note: Capacities for TS China Special Equipment Certification products may vary; please consult the manufacturer.)

Steam (Saturation Temperature) - Pressure Vessel Structure Standard

Pressure (MPa)	0.1	0.2	0.3	0.4	0.5
25A	181	263	353	444	532
40A	478	694	932	1174	1407
50A	636	925	1242	1563	1874

Steam - Boiler Structure Standard

Pressure (MPa)	0.1	0.2	0.3	0.4	0.5
25A	177	258	340	424	504
40A	467	683	900	1120	1333
50A	622	910	1198	1491	1775

Air (20℃) - Pressure Vessel Structure Standard

Pressure (MPa)	0.1	0.2	0.3	0.4	0.5
25A	293	425	571	717	863
40A	774	1124	1510	1895	2280
50A	1030	1497	2010	2523	3036