Fushiman RFD42 type back pressure valve for liquids

Manufacturer: Fushiman Co.,LTD.
Model: RFD42

Model	Nominal diameter	Primary measurement pressure range	Maximum operating temperature	Body Material	Connection
RFD42	40–300	0.05 to 2.0 MPa	80°C	FC,, SCPH	Flanges

This valve is a basic (main) valve that can be equipped with various pilot valves and accessories, making it suitable for multiple applications. It is one of the 42-series valves.
Since it is a pilot-operated type, it has a large capacity relative to its nominal diameter. Additionally, the offset is small.
For registered certified valves for automatic pressure adjustment in fire protection equipment, please refer to the separate listing (page 117).

Specifications and Materials

Fluid	Primary Side Pressure Setting Range (MPa)	Temperature (°C)	Main Valve (OD3 Type) Main Component Materials			Pilot Valve (RPD52-2 Type) Main Component Materials			Pipe Connection (Main Valve)
Fluid	Primary Side Pressure Setting Range (MPa)	Temperature (°C)	Valve Box & Cover	Valve Body / Diaphragm	Valve Seat	Valve Box	Spring Protection Cylinder	Valve Body / Diaphragm	Pipe Connection (Main Valve)
Water, Light Oil, and Other Non-Corrosive Liquids	0.05–0.25	0–80	Cast Iron (Wetted parts epoxy resin coating)	Synthetic Rubber	Brass	Brass	Cast Iron	Synthetic Rubber	Flange JIS 10K Full Face
	0.2–0.65	0–80	Cast Iron (Wetted parts epoxy resin coating)	Synthetic Rubber	Brass	Brass	Cast Iron	Synthetic Rubber	Flange JIS 16K Full Face
	0.6–1.2	0–80	Cast Iron (Wetted parts epoxy resin coating)	Synthetic Rubber	Brass	Brass	Cast Iron	Synthetic Rubber	Flange JIS 20K Flat Seat
	1.0–2.0	0–80	Cast steel	Synthetic Rubber	Brass	Brass	Cast Iron	Synthetic Rubber	Flange JIS 20K Flat Seat

Notes:

The valve box can also be made of stainless steel cast steel.
ASME Class 150 and 300 can also be manufactured.
Valve boxes with a nylon coating (for temperatures of 60°C or lower) can also be manufactured.
For water hammer prevention, please use the SFD42 type (refer to page 110).

Performance

Maximum Differential Pressure Setting	1.5 MPa
Minimum Differential Pressure Setting	0.04 MPa
Offset	Approximately 10% or less of the set pressure (minimum value: ~0.04 MPa)
Shutoff Pressure Drop (¹)	0.01–0.03 MPa (for pressure setting range 0.05–0.25 MPa)
	0.02–0.05 MPa (for pressure setting range 0.2–0.65 MPa)
	0.06–0.09 MPa (for pressure setting range 0.6–1.2 MPa)
	0.08–0.12 MPa (for pressure setting range 1.0–2.0 MPa)
Maximum Usable Viscosity Fluid	Light oil 20 mm²/s or lower
Minimum Adjustable Flow Rate (Water) (¹)	5–15 L/min
Valve Seat Leakage	0.01% or less of the rated flow rate

Note (¹): Applicable under specific operating conditions.

Cv Value

Nominal Diameter	40	50	65	80	100	125	150	200	250	300
Cv	22.5	40	62.5	90	160	250	360	640	1000	1440
Maximum Flow Rate (Water) (L/min) (²)	533	800	1300	2000	3000	5000	7700	12000	17000	24000

Note (²): For liquids other than water, divide by √γ (γ = specific gravity of the liquid, assuming water at 4°C as 1).

Piping Example

Space Required for Disassembly and Maintenance

Nominal Diameter	40	50	65	80	100	125	150	200	250	300
Upward Space from Pipe Center (mm)	450	460	470	480	500	530	570	670	870	1040

The installation orientation can be either horizontal or vertical piping. However, avoid installing it upside down or horizontally on its side.
It is recommended to install a straight pipe section of at least:

600 mm (for nominal diameter 40)
900 mm (for nominal diameters 50–100)
1200 mm (for nominal diameters 125–150)
1600 mm (for nominal diameters 200–250)
2000 mm (for nominal diameter 300)

before and after the back pressure valve to ensure stable operation.

Structure and Dimensions

Dimensions and Weight

Specification/Nominal Diameter	Label	40	50	65	80	100	125	150	200	250	300
Valve Box Cast Iron (JIS 10K)	L	220	260	290	330	390	470	530	670	800	900
	H1	75	90	97	110	125	155	175	220	275	333
	H2	260	280	300	300	320	320	345	424	538	640
	A	110	120	135	145	180	200	220	270	320	375
	E	125	113	105	125	147	177	207	258	310	370
	Weight	16	20	32	39	62	94	138	240	420	695
Valve Box Cast Iron (JIS 16K)	L	220	260	290	334	394	474	534	678	808	908
Valve Box Cast Steel / Stainless Steel Cast Steel (JIS 20K)	L	216	260	286	330	390	480	536	684	816	916