Yoshitake AF-4M is a full bore safety valve with an open type structure. Designed for steam, air, and other non-dangerous fluids, it offers a larger discharge capacity compared to standard lift-type safety valves. The AF-4 series includes the AF-4 model, which features a lift lever mechanism allowing manual discharge inspection at over 75% of the opening pressure, while the AF-4M is the open type without a lever.

Features

• Larger discharge capacity than lift type.
• Due to lift lever mechanism a discharge inspection can be manually performed at more than 75% of the opening pressure (AF-4).

AF-4M

AF-4

Specifications

Structure	Open type
Application	Steam, Air, Other non-dangerous fluids
Working pressure	0.1-1.0 MPa
Maximum temperature	220°C
Material (Valve case)	Ductile cast iron
Material (Valve, valve seat)	Stainless steel
Connection	JIS 10K FF flanged JIS 10K RF flanged *

* JIS 10K RF flanged when nominal size is 100A and larger.

Dimensions and Weights

Nominal size	Inlet × Throat × Outlet	Flow area (mm²)	Lift R (mm)	L (mm)	H1 (mm)	HL (mm)	Hx (mm)	Inlet Flange	T (mm)	Outlet Flange	Weight (kg)
25A	25×16×40	200.9	3.7	100	100	358	335	25A	26	40A	12
40A	40×26×65	530.6	6.0	120	120	410	408	40A	28	65A	21
50A	50×30×75	706.5	6.8	130	130	459	453	50A	30	80A	27

Note

Inlet flange is according to JIS B 2239 10K FF or JIS B 2239 10K RF except for the thickness "T" which is thicker than specified in JIS. Outlet is JIS B 2239 10K FF flanged.

At the Time of Ordering

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.)

<Inlet: JIS 10K FF flanged>

<Inlet: JIS 10K RF flanged>

Certified Capacity Table for AF-4, 4M

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
25A	181	263	353	444	532	620	707	793	879	966
40A	478	694	932	1174	1407	1638	1868	2095	2323	2552
50A	636	925	1242	1563	1874	2182	2487	2790	3093	3398
65A	1132	1644	2208	2780	3332	3879	4422	4960	5500	6042

<Boiler 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
25A	177	258	340	424	504	586	668	749	829	911
40A	467	683	900	1120	1333	1550	1764	1980	2191	2406
50A	622	910	1198	1491	1775	2063	2350	2636	2918	3204
65A	1106	1619	2131	2651	3156	3669	4177	4687	5187	5696

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
25A	293	425	571	717	863	1009	1155	1301	1447	1593
40A	774	1124	1510	1895	2280	2666	3051	3436	3822	4207
50A	1030	1497	2010	2523	3036	3550	4063	4576	5089	5602

Structure and Parts

Open type without a lever

No.	Part Name	Material
30	Bearing Cover	Rolled Steel (SS400)
29	Bearing	Bearing Steel (SUJ)
28	Top Spring Plate	Steel
27	Name Plate	Stainless Steel (SUS304)
25	Lock Nut	Brass (C3604)
24	Nipple	Carbon Steel Pipe (SGP)
23	Set Screw	Chromium Molybdenum Steel (SCM435)
22	Stud Bolt	Rolled Steel (SS400)
21	Nut	Rolled Steel (SS400)