Yoshitake GD-4B is a pressure reducing valve designed for air and other non-dangerous fluids. It features a diaphragm with a large pressure sensing area for high set pressure accuracy and a pressure balance structure. Since there is no gland part, it prevents outside leakage, ensuring a safe and reliable operation.

Features

1. Diaphragm with a large pressure sensing area has accuracy to high set pressure.
2. No outside leakage since there is no gland part.
3. Adopts pressure balance structure.

Specifications

Application	Air, Other non-dangerous fluids
Nominal size	15-50A / 65-150A
Diaphragm diameter (mm)	φ400 / φ340 / φ256
Inlet pressure	800 kPa (15-50A) / 500 kPa (65-150A)
Reduced pressure (kPa)	2-5 / 4-6 / 5-10 / 6-10 / 10-25 / 50-100 / 100-200 (15-50A) 2-4 / 10-20 / 20-50 / 50-100 / 100-200 (65-150A)
Adjusted reduced pressure	85% or less of inlet pressure (gauge pressure)
Minimum differential pressure	1 kPa / 2 kPa / 3 kPa
Maximum pressure reduction ratio	20:1 (15-50A) / 15:1 (65-150A)
Application temperature	5-80°C
Valve seat leakage	No leakage

Material

• Body: Cast iron *1
• Valve: NBR
• Valve seat, Spindle: Stainless steel
• Diaphragm: NBR
• Connection: JIS 10K FF flanged

*1 Available with carbon steel or stainless steel body for 20A to 150A.

WARNING

Use on a compressed air system with dry air from oil-free compressors may cause deterioration of rubber parts in a very short time (ozone crack). Please consult with us before such installation.

Dimensions (mm) and Weights (kg)

Nominal size	L	H (Ha)	H (Hb)	H₁	Weight
15A	166	575	590	95	27
20A	170	575	590	95	27
25A	170	575	590	95	28
32A	180	585	600	100	28
40A	180	585	600	100	29
50A	180	605	620	110	31
65A	215	700	715	125	39
80A	260	715	730	140	48
100A	300	785	800	165	64
125A	360	840	855	190	88
150A	382	870	885	220	118

INFO

Dimension H will be different depending on diaphragm diameter. (Ha: φ256, Hb: φ340, φ400). The value of product weights are when diaphragm diameter is 256. Please add 5kg for φ340, and 9kg for φ400.

Specifications Selection Chart

Nominal size 15A-50A

Nominal size 65A-150A

Flow Characteristic Chart

Nominal size	Shut-off pressure rise
15A-50A	Within 10% of set pressure
65A-100A	Within 15% of set pressure
125A-150A	Within 20% of set pressure

Nominal size	Offset pressure
15A-50A	Within 20% of set pressure
65A-150A	Within 25% of set pressure

TIP

• Set the safety factor at 80 to 90%.