Yoshitake GD-27S is a direct-type pressure reducing valve designed for cold and hot water applications. It features a cast stainless steel body, JIS 10K FF flanged connection, and a closed structure that keeps fluid inside even if the diaphragm is damaged. The pressure balance structure maintains a constant reduced pressure without being affected by fluctuations in the inlet pressure.

Features

• Wetted parts are made of corrosion-resistant material to prevent rusty water.
• Reduced noise.
• Pressure balance structure can keep the reduced pressure at a constant level without being affected by inlet pressure.
• Closed structure keeps fluid inside even if the diaphragm is damaged or broken.
• Maintenance and inspection can be conducted easily by disassembling simply from the upper side.
• Compact and lightweight design makes piping works easy.

Specifications

Specification	Value
Application	Cold and hot water
Inlet pressure	1.0 MPa or less
Reduced pressure	(A) 0.05 - 0.35 MPa (B) 0.30 - 0.70 MPa
Minimum differential pressure	0.05 MPa
Maximum pressure reduction ratio	10:1
Application temperature	5 - 90°C
Body / Valve seat	Cast Stainless Steel
Valve disc / Diaphragm	EPDM (Available with FKM except NE models)
Connection	JIS 10K FF flanged

INFO

• A strainer (40 mesh) is incorporated in sizes up to 50A. Sizes 65A to 100A do not include a strainer.
• Pressure gauge connection port is JIS R1/8.

Dimensions and Weights

Nominal size	L (mm)	H (mm)	H1 (mm)	Weight (kg)
20A	160	170	41	3.9
25A	160	170	41	4.8
32A	200	224	57	8.0
40A	200	224	57	8.3
50A	220	239.5	61	10.8
65A	220	329	77	20.6
80A	230	345	82	22.0
100A	270	412	94	34.5

Rated Flow Rate

(The differential pressure before and after the valve is 0.15 MPa or more.)

Nominal size	20A	25A	32A	40A	50A	65A	80A	100A
Rated flow rate (L/min)	40	60	100	150	250	300	450	700

If the differential pressure before and after the valve is less than 0.15 MPa, select a proper nominal size from the appropriate chart shown below.

Flow Rate Chart

Nominal size: 15A to 50A

Nominal size: 65A to 100A

Performance Characteristics

Noise Characteristic Chart

Pressure Characteristic Chart This chart shows variation in reduced pressure when the inlet pressure of 0.6 MPa is changed between 0.15 MPa and 1.0 MPa while the reduced pressure is set at 0.1 MPa.

Flow Characteristic Chart

Offset pressure

Nominal size	Pressure range	Reduced pressure range	Offset pressure
15-100A	A	0.05-0.35 MPa	Within 0.05 MPa
15-100A	B	0.30-0.70 MPa	Within 0.10 MPa

Operation

The spring is compressed by the adjusting screw, the diaphragm is pushed down, and thereby the disc directly connected to it is opened. Fluid coming in from the inlet side flows out from the upper part of the disc to the outlet side, and passes through the reduced pressure detection hole, and is led to the bottom of the diaphragm. The load of the spring and the reduced pressure act to the diaphragm, and the upper and lower force keeps a balance and regulates the valve opening. As a result, the diaphragm keeps the reduced pressure constant.

Installation and Maintenance

WARNING

• Before installing the product in the piping, be sure to remove foreign substances and scale from the piping.
• Be sure to install a strainer at the inlet side of the product of nominal size 65A to 100A.
• Install a safety relief valve for equipment protection at the outlet side of the product.
• The product can be installed either horizontally or vertically (nominal size 15A to 100A).

Adjusting Procedure

1. Close the stop valves at the inlet and outlet sides of the reducing valve, and take adequate time to blow out fluid by using a bypass line.
2. Fully open the stop valve at the inlet side slowly, and open the stop valve at the outlet side so that a little fluid can flow through.
3. Remove the domed cap nut and turn the adjusting screw while watching the pressure gauge at the outlet side. Turn to the right (clockwise) to increase the reduced pressure, or to the left (counterclockwise) to decrease it.
4. Fully open the stop valve at the outlet side slowly.
5. After the adjustment is complete, tighten the domed cap nut.