The Yoshitake AL-301T is a closed type safety relief valve designed for applications involving air, cold and hot water, oil, and other non-dangerous fluids. It features a lift type, dash-pot structure with excellent airtightness due to its PTFE valve disc. The trim parts (valve and valve seat) are made of stainless steel, providing outstanding corrosion resistance and durability. The valve operates at pressures up to 1.3 MPa (with JIS 16K FF flanges for pressures above 1.0 MPa) and temperatures up to 150°C.

Features

1. Due to using valve disc of polytetrafluoroethylene (PTFE) material on the valve parts, the airtightness of valve seat is excellent.
2. The trim parts (valve, valve seat) of AL-301T is stainless steel material with outstanding corrosion resistance.

Specifications

Model	AL-301T
Structure	Closed type
Application	Air, Cold and hot water, Oil, Other non-dangerous fluids
Working pressure	0.05-1.3 MPa *1
Maximum temperature	150°C
Material (Valve case, spring case)	Ductile cast iron
Material (Valve, valve seat)	Stainless steel • PTFE
Connection	JIS 10K FF flanged, JIS 16K FF flanged *2

*1 Please contact us if working pressure is between 1.31 MPa and 1.6 MPa. *2 JIS 16K FF flanged when working pressure is more than 1.0 MPa.

Dimensions and Weights

Nominal size	L (mm)	H1 (mm)	H (mm)	D (mm)	Flow area πDl (mm2)	Weight (kg)
15A	90	108	245	29	66.1	4.7
20A	90	108	245	29	66.1	5.0
25A	90	108	245	29	66.1	6.2
32A	91	115	285	37	107.6	8.6
40A	91	115	285	37	107.6	8.8
50A	105	132	311	50	196.4	12.6

Operation

Opening operation

As the inlet pressure approaches the opening pressure, the force of fluid pushing up the valve approaches the force pressing down the valve. The safety relief valve starts to discharge when the inlet pressure reaches around 3% below the opening pressure, and the fluid accumulates gradually on the pressure groove. When the fluid pressure reaches the opening pressure, the valve pops.

Closing operation

Since the inlet pressure of the safety relief valve decreases when the fluid is released into the atmosphere by the pop action of valve, the fluid lift force is lowered. At this point, the repelling force of the spring becomes larger than the force of fluid lift and thus the valve closes.

Certified Capacity Table for AL-301T

• For air (20°C) (Pressure vessel structure standard) (kg/h)

Nominal size \ Pressure MPa	0.05	0.1	0.2	0.3	0.4	0.5	0.6	0.7	0.8	0.9	1.0	1.1	1.2	1.3
15A, 20A, 25A	84	109	159	213	268	322	377	432	486	541	595	650	704	759
32A, 40A	136	178	259	347	436	525	614	703	792	880	969	1058	1147	1236
50A	249	325	473	635	797	959	1121	1283	1445	1607	1769	1932	2094	2256

• For water (accumulation: 25%) (Yoshitake standard) (m³/h)

Nominal size \ Pressure MPa	0.05	0.1	0.2	0.3	0.4	0.5	0.6	0.7	0.8	0.9	1.0	1.1	1.2	1.3
15A, 20A, 25A	0.8	1.1	1.6	2.0	2.3	2.6	2.8	3.1	3.3	3.5	3.7	3.9	4.0	4.2
32A, 40A	1.3	1.9	2.7	3.3	3.8	4.2	4.7	5.0	5.4	5.7	6.0	6.3	6.6	6.9
50A	2.4	3.5	4.9	6.0	7.0	7.8	8.5	9.2	9.9	10.5	11.0	11.6	12.1	12.6

Installation

Warning

1. Do not install any closing device such as a stop valve at inlet and outlet sides of the product.
2. Do not disassemble the product unnecessarily. Failure to follow this notice may prevent the product from functioning properly and lead to danger.
3. Lead outlet pipe to a place where there is no risk of physical damage even if fluid blows out. Failure to follow this notice may result in injury and scalds in case of fluid blow out.
4. Do not apply viscous fluid that may make fixation of the valve and valve seat. Failure to follow this notice may prevent the product from functioning properly.

Caution

1. Before installing the product, remove foreign substances and scale from the piping.
2. When installing the product, match the direction of fluid flow with the inlet and outlet of the product respectively.
3. Install the product in a way that excessive load, torque or vibration cannot be applied to the product.
4. Inner diameters of pipe mount and of exhaust pipe shall be equal to or larger than those of each inlet and outlet of the product.
5. Install the product in a posture in which the stem of the adjusting screw is vertical to the ground and the cap faces upward. Preferably attach the product directly to a pressure vessel. In addition, place the product in a position where maintenance and inspection can be done easily.
6. When installing an exhaust pipe, its inner diameter shall be more than that of the product outlet to avoid improper back pressure.

Operating Procedure

Warning

1. Do not apply the product to devices which do not allow any valve seat leakage. The product has allowable valve seat leakage and does not close completely (the valve seat leakage cannot be zero).
2. Do not touch the product with bare hands when fluid is hot. Failure to follow this notice may scald your skin.
3. Do not look down or touch the product outlet. Failure to follow this notice may result in injury or scalds in case that fluid blows out suddenly.
4. Do not turn the adjusting screw unless it is necessary. Failure to follow this notice may cause improper and dangerous operation such as blowout at a lower pressure than the set pressure or not blowing at the set pressure.

Opening pressure adjustment

1. Turn the cap counterclockwise and remove it.
2. Loosen the lock nut by turning it counterclockwise using a spanner.
3. To increase the set pressure, turn the adjusting screw clockwise using a spanner.
4. To decrease the set pressure, turn the adjusting screw counterclockwise using a spanner.
5. After adjustment is completed, tighten the lock nut and then the cap.