Yoshitake GD-41 series is a highly durable direct type pressure reducing valve designed for space saving and excellent corrosion resistance. The wetted parts are made of cast stainless steel (SCS14A and SUS316), and the diaphragm contact surface is completely covered with PTFE, making it highly durable and suitable for a wide range of fluids including cold and hot water, air, carbon dioxide gas, nitrogen gas, and sterilization steam.

Thanks to its built-in pressure balance structure, the valve keeps the reduced pressure constant without being affected by fluctuations in the inlet pressure. The closed structure prevents fluid from flowing to the outside, providing a high level of safety and reliability for various industrial applications. Selected models in the family, such as the GD-41N and GD-43N, are approved by the JWWA (Japan Water Works Association).

Features

• Compact & Resource-saving: Space saving and resource saving are achieved. Used materials are clearly shown on the body and lower cap, making separate collection of parts for resource recycling easy.
• Corrosion Resistant: Cast stainless steel (SCS14A and SUS316) is used for all wetted parts, significantly improving corrosion resistance. Special fluorine-contained rubber parts offer additional chemical and heat resistance.
• Durable Diaphragm: PTFE covers the diaphragm's contact surface to the fluid, making the diaphragm less liable to deteriorate and highly durable over long periods of use.
• Stable Output: The pressure balance structure can keep the reduced pressure at a constant level without being affected by the inlet pressure.
• Hygienic Applications: Perfectly suited to piping washing, system washing, sterilization washing, and steam for sterilization.
• Flexible Installation: Horizontal or vertical installation is possible.

Specifications

Model	GD-41	GD-43-10	GD-43-20	GD-41N	GD-43N-10	GD-43N-20
Application	Cold and hot water / Steam for washing or sterilization
Inlet pressure	0.07-2.0 MPa (0.2 MPa or less for steam for washing or sterilization) *
Reduced pressure	(A) Yellow spring: 0.02-0.1 MPa (B) Red spring: 0.1-0.25 MPa (C) Black spring: 0.25-0.5 MPa
Minimum differential pressure	0.05 MPa
Maximum pressure reduction ratio	Cold and hot water: 10:1
Fluid temperature	5-90°C (Max temperature of steam for washing or sterilization is 130°C)
Body Material	Cast Stainless steel (SCS14A)
Valve disc Material	Special synthetic rubber (special FKM)
Diaphragm Material	Heat-resistant synthetic rubber and PTFE
Connection	JIS Rc screwed	JIS 10K FF flanged	JIS 20K RF flanged	JIS Rc screwed	JIS 10K FF flanged	JIS 20K RF flanged

Precautions for Steam

• The inlet pressure of the GD-43-10 and GD-43N-10 is 0.07 to 1.0 MPa.
• If using for washing steam or sterilization steam, be sure that the maximum temperature is 130°C and avoid continuous use for more than 30 minutes. Allow an interval of at least four hours between steam flows.

Dimensions and Weights

GD-41 / 41N (Screwed Connection)

Nominal size	d	Weight (kg)
15A	Rc 1/2	1.2
20A	Rc 3/4	1.1
25A	Rc 1	1.0

GD-43 / 43N (Flanged Connection)

Size	D	C	g	t	f	n-h	Weight (kg)
15A	95	70	51	14 (12)	1	4-15	2.8 (2.6)
20A	100	75	56	16 (14)	1	4-15	3.0 (2.9)
25A	125	90	67	16 (14)	1	4-19	4.0 (3.7)

Note: The values in parentheses are the dimensions/weights of the GD-43-10 and GD-43N-10.

Flow and Pressure Characteristics

Flow Characteristic Chart

Set pressure	Offset pressure
0.2 MPa or less	Within 0.05 MPa
More than 0.2 MPa	Within 0.08 MPa

Pressure Characteristic Chart

This chart shows the variation in reduced pressure when the inlet pressure of 0.25 MPa is changed up to 2.0 MPa while the reduced pressure is firmly set at 0.20 MPa.

Installation and Operation

General Safety Warning

When installing a safety valve at the outlet side of the pressure reducing valve, always connect a blow-off pipe to the outlet of the safety valve to lead the possible discharged fluid to a safe location.

Installation Precautions

• Be sure to install a strainer (60 mesh or more recommended) at the inlet side of the pressure reducing valve to prevent the ingress of foreign substances or scale.
• Install a safety valve at the outlet side to fully protect the downstream equipment.
• Attach a pressure gauge to both the inlet and outlet to regulate pressure correctly.
• When installing a quick opening/closing device (e.g., solenoid valve), keep a distance of at least 3 meters from the pressure reducing valve.

Maintenance and Component Replacement

To maintain optimal functions and performance of the pressure reducing valve, perform periodic checks and replace expendable parts based on usage frequency.

Standard Replacement Intervals:

• Diaphragm set: 3 years
• Disc: 3 years
• O Ring: 3 years