The Yoshitake GP-1000H and GP-1000HEN are pilot-operated, piston-type pressure reducing valves designed specifically for steam applications. They respond sharply to fluctuations in inlet pressure and changes in flow rate, ensuring the reduced pressure is maintained at a constant level. The GP-1000HEN model complies with the face-to-face dimensions of the EN standard (except for 15A), making it an easy replacement for existing valves. Both models offer a wide set pressure range and are compliant with the SHASE-S106 standard for pressure reducing valves.

Features

1. The GP-1000HEN is an easy replacement for existing valves because it complies with face-to-face dimensions of the EN standard (except for 15A).
2. The valve responds very sharply to the fluctuation of inlet pressure and the change of the flow rate, so that the reduced pressure can be kept at a constant level.
3. Pressure adjustment is easy, and the set pressure range is wide.
4. Compliant with the standard of SHASE-S106 Pressure Reducing Valves (by the Society of Heating, Air-Conditioning and Sanitary Engineers of Japan).

Specifications

Specification	GP-1000HEN	GP-1000H
Application	Steam	Steam
Inlet pressure	0.1-1.6 MPa	0.1-1.6 MPa
Reduced pressure	(A) 0.05-0.9 MPa (B) 0.9-1.4 MPa	(A) 0.05-0.9 MPa (B) 0.9-1.4 MPa
Minimum differential pressure	0.05 MPa	0.05 MPa
Maximum pressure reduction ratio	20:1	20:1
Maximum temperature	220°C	220°C
Valve seat leakage	0.01% or less of rated flow rate	0.01% or less of rated flow rate
Body Material	Ductile cast iron	Ductile cast iron
Main valve, valve seat	Stainless steel	Stainless steel
Pilot valve, pilot valve seat	Stainless steel	Stainless steel
Piston, cylinder	Stainless steel	Stainless steel
Diaphragm	Stainless steel	Stainless steel
Connection	EN PN25 flanged	JIS 16K FF flanged ASME Class 300 flanged

Note: For 15A, 20A, ASME flange is not available.

Dimensions and Weights

Nominal size	L (GP-1000HEN)	L (GP-1000H)	H	H1	Weight (GP-1000HEN)	Weight (GP-1000H)
15A	150	150 (-)	291	64	8.0 kg	8.0 (-) kg
20A	150	155 (-)	291	64	8.5 kg	8.5 (-) kg
25A	160	160 (160)	300	67	10.0 kg	10.0 (10.0) kg
32A	180	190 (180)	333	82	14.0 kg	14.0 (14.0) kg
40A	200	190 (200)	333	82	15.5 kg	14.5 (15.5) kg
50A	230	220 (230)	353	93	21.0 kg	20.0 (21.0) kg
65A	290	245 (278)	357	100	30.0 kg	30.0 (30.0) kg
80A	310	290 (310)	404	122	37.0 kg	35.0 (37.0) kg
100A	350	330 (350)	450	144	57.0 kg	52.5 (57.0) kg

Note: The values in parentheses are the dimensions of ASME Class 300 flanged.

Selection Charts

Specifications Selection Chart

Find the intersection point of the inlet and reduced pressures. If the intersection point is within range (A) in the chart, the pressures are controllable with a single pressure reducing valve. They can be controlled by two-stage pressure reduction if the intersection point is within range (B). The valve does not fulfill specified performance in range (C).

Safety Valve Setting Pressure

Reduced pressures (MPa)	Safety valve setting pressure (MPa)
0.03~0.1	Reduced pressures + more than 0.05
0.1~0.4	Reduced pressures + more than 0.08
0.4~0.6	Reduced pressures + more than 0.1
0.6~0.8	Reduced pressures + more than 0.12
0.8~1.4	Reduced pressures + 15%

Pressure Characteristic Chart

This chart shows variation in reduced pressure when the inlet pressure of 1.0 MPa is changed between 0.3 MPa and 1.6 MPa while the reduced pressure is set at 0.1 MPa.

Flow Characteristic Chart

• Shut-off pressure rise: Within 0.02 MPa
• Offset pressure: Within 0.03 MPa (when the set pressure is between 0.05 MPa and 0.1 MPa); Within 0.05 MPa (when the set pressure is more than 0.1 MPa and 1.4 MPa or less)

Table of Corrected Cv Values

Nominal size	15A	20A	25A	32A	40A	50A	65A	80A	100A
Rated Cv values	1	2.3	4	6.5	9	16	25	36	64

Note on Cv Correction

When the reduced pressure is within either of the ranges shown below, calculate the corrected Cv value by multiplying the rated Cv value by the correction factor C obtained from the chart below.

• When the inlet pressure is between 0.7 MPa and 1.0 MPa and the pressure reduction ratio is more than 10:1
• When the inlet pressure is more than 1.0 MPa and the reduced pressure is 0.4 MPa or less

Nominal Sizes Selection Chart (For Steam)

Operation

The pressure-reducing valve reduces pressure by throttling the valve. The valve is composed of the main valve and main valve seat for throttling, and adjusting spring, diaphragm, pilot valve, and piston for pressure sensing and activation.

1. When the pressure-reducing valve is mounted correctly, releasing the compression of the adjusting spring allows the spring to close the main valve and pilot valve. Slowly open the gate valve and allow the high-pressure fluid to flow in. Inlet pressure is applied to the downside of the main valve. High-pressure fluid passes through the strainer via the inlet pressure passage to also apply inlet pressure to the downside of the pilot valve.
2. Turning the adjusting screw clockwise compresses the spring, which flexes the diaphragm to open the pilot valve.
3. Inlet pressure via the inlet pressure passage and pilot valve enters the upside of the piston. The pressure overrides the pressure on the downside of the main valve and the load of the main valve spring, to open the main valve. The fluid then begins to flow from the inlet side.
4. Reduced pressure is led to the diaphragm chamber via the reduced pressure sensing port. The diaphragm receives the reduced pressure to be balanced with the adjusting spring load, and controls the pilot valve travel.
5. The change of pilot valve travel changes the flow rate of fluid to the upside of the piston, and controls the main valve travel to obtain appropriate reduced pressure.

Installation and Piping

Example of Piping

Precautions during installation

• Because of heavy weight, hold the valve with lifting equipment while piping. Failure to do so may result in injury due to dropping the valve.
• In case installing a safety valve as a safety device at the outlet side, joint relief pipe at the outlet of the safety valve and guide it to a safe place where steam can relief out.
• Remove foreign matter and scales from the lines before connecting the valve.
• Install a strainer (80 mesh) at the valve inlet side.
• Install a pressure gauge at both the inlet and outlet sides of the valve.
• Install a steam trap to the inlet sides of the valve to prevent drainage problems.
• When installing quick open and close valves, such as a solenoid valve, install it at the inlet side as much as possible, and secure at least 3 m from the valve.
• When pressure reducing in two stages, secure at least 3 m between the valves.
• Install the valve perpendicularly to horizontal lines.
• Provide a by-pass line.

Installation Space

Provide space on the top and bottom of the valve so that the valve can be easily disassembled and inspected.

Nominal size	A (mm)	B (mm)
15A, 20A, 25A	315	125 (15A, 20A) / 135 (25A)
32A, 40A	335	155
50A	345	175
65A	355	190
80A	375	225
100A	395	265

Troubleshooting

Problem	Cause	Solution
Pressure does not reach the desired value.	Incorrect pressure is being used. Strainer is clogged. Foreign matter exists between piston and cylinder. Piston ring is damaged. Nominal size is too small for the specifications. Pressure is not adjusted correctly. Strainer installed before pressure reducing valve is clogged. Pressure gauge is faulty.	Correct the pressure. Disassemble and clean the strainer. Disassemble and remove the foreign matter. Polish scratches away using paper. Change parts if scratches still exist. Replace the piston ring. Change the nominal size appropriately. Observe the adjustment procedures and readjust pressure. Disassemble and clean it. Replace it.
Reduced pressure raises above than the specified value.	Foreign matter exists between main valve and main valve seat, or scratches exist. Foreign matter exists between pilot valve and pilot valve seat, or scratches exist. Foreign matter exists between piston and cylinder. Trap is not provided for dead-end line. By-pass valve is leaking. Diaphragm is damaged.	Disassemble and remove the foreign matter. Lap the main valve and main valve seat if scratched. Change parts if scratches still exist. Disassemble the pilot valve assembly, and clean or replace it. Disassemble and remove the foreign matter. Polish scratches away using paper. Install a trap. Repair or replace it. Replace the diaphragm.
Abnormal noise is heard.	Nominal size is too large for the specifications. Pressure reducing ratio is too large. Drainage problem is caused. An abrupt OPEN/CLOSE valve is located too close to the pressure reducing valve. Outlet pipe is too small.	Change the nominal size appropriately. Reduce pressure in two stages. Install a trap. Allow as much space as possible between the valves. Select a pipe size that will produce a flow velocity of 30m/s or less.

Maintenance and Disassembly

Warning

Be sure that the stop valves at the inlet and outlet side of the pressure reducing valve are closed and all internal pressure and condensate have discharged before disassembling the valve. While disassembly, drain flow out from the valve, so catch it by container.

Disassembly Steps

1. Pilot valve: Loosen the lock nut and turn the adjusting screw to release the spring (no compression). Remove the bolts of the spring chamber. Remove the spring chamber, spring, top spring plate, bottom spring plate, and diaphragm. Remove the pilot valve assembly using a ring spanner or socket wrench.
2. Piston: Remove the bolts of the top cover and the top cover. Pick up the spindle, and remove the piston ring and the inner ring.
3. Main valve: Remove the bolts of the bottom cover. Remove the bottom cover, main valve spring, and main valve.

Exploded Drawing

No.	Name of parts	Replace period
5	Diaphragm	2 years
16	Piston ring	3 years
17	Inner ring	3 years
19, 20	Pilot valve assembly	5 years
24	Gasket	5 years
26, 27	Gasket	2 years
28	Strainer	5 years
30	Gasket	2 years