Key Features
✓ Direct-acting pressure sustaining / back pressure valve
✓ Automatically maintains a constant minimum upstream pressure
✓ 1–5 Bar or 4–10 Bar adjustable pressure ranges
✓ Alternative pressure ranges available on request
✓ Balanced piston and diaphragm design for stable regulation
✓ Fast response to changing downstream flow demand
✓ No external pilot controller required
✓ DN15 to DN150 flanged connections
✓ PN16 flanges as standard
✓ Optional ANSI 150 lb, JIS10K or PN25 flanges
✓ Heavy-duty 316 stainless steel construction
✓ 316L welded flanges on DN15–DN50 models
✓ CF8M stainless steel flanges on DN65–DN150 models
✓ Optional Duplex stainless steel construction
✓ Maximum inlet pressure 25 Bar
✓ Factory pressure tested to 35 Bar
✓ High flow capacity from Cv 2.5 to 170 according to valve size
✓ Stainless steel upstream pressure gauge included
✓ NBR seals as standard with optional FKM (Viton) or EPDM
✓ Maximum media temperature up to +100°C with FKM or EPDM seals
✓ Suitable for compressed air and compatible industrial gases
✓ Suitable for water, pure water and RO water
✓ Suitable for compatible light oils up to 40 cSt
✓ Precision UH-ring sealing for low leakage and long service life
✓ Heavy-duty flanged design for industrial process pipework
Description
Flanged 316 Stainless Steel Pressure Sustaining Valve – Z-Tide Industrial RFF Series
The Z-Tide Industrial RFF Series is a heavy-duty direct-acting pressure sustaining and back pressure valve designed to automatically maintain a constant minimum upstream pressure in high-flow water, compressed air, gas and compatible industrial process systems.
Manufactured from 316 stainless steel with a balanced piston and diaphragm design, the RFF provides stable and repeatable upstream pressure regulation despite changes in downstream demand. Available from DN15 to DN150 with flow capacities up to Cv 170, the RFF is particularly suited to water treatment, RO systems, chemical processing and industrial installations requiring dependable back pressure control with robust flanged connections.
Valve Function & Operation
Function: Direct-acting pressure sustaining valve
Alternative function: Back pressure valve (BPV)
Operating principle: Balanced piston and diaphragm
The valve automatically regulates flow to maintain the selected minimum pressure on the upstream side. If upstream pressure begins to fall below the set point, the valve restricts downstream flow to sustain the required pressure. As upstream pressure rises, the valve opens further to permit increased flow while maintaining the selected back pressure.
Pressure gauge: Displays sustained inlet / upstream pressure
Flange sizes:
DN15
DN20
DN25
DN32
DN40
DN50
DN65
DN80
DN100
DN150
Standard flange: PN16
Optional flange standards:
ANSI 150 lb
JIS10K
PN25
Pressure & Regulation
Maximum inlet pressure: 25 Bar
Pressure tested: 35 Bar
Back pressure adjustment ranges:
1 to 5 Bar
4 to 10 Bar
Alternative pressure ranges available on request
Minimum media temperature: -15°C
Maximum media temperature:
NBR: +60°C
FKM (Viton): +100°C
EPDM: +100°C
Maximum media viscosity: 40 cSt
Flow capacity: Cv 2.5 to 170 according to valve size
Construction & Materials
Body: 316 stainless steel
Optional body: Duplex stainless steel
Flanges:
DN15–DN50: 316L stainless steel welded flanges
DN65–DN150: CF8M stainless steel flanges
Upper cover: 316 stainless steel
Piston: 316 stainless steel
Shaft: 316 stainless steel
Diaphragm: NBR or FKM
UH-ring: NBR or FKM
Spring: Spring steel
Lower cover: 316 stainless steel
Pressure gauge: Stainless steel gauge included
Standard seals: NBR
Optional seals:
FKM (Viton)
EPDM
Media Compatibility
✓ Compressed air
✓ Industrial gases
✓ Water
✓ Pure water
✓ Reverse osmosis (RO) water
✓ Light oils
✓ Fluids under 40 cSt compatible with the valve materials
Performance & Design
✓ Maintains the selected minimum upstream pressure regardless of normal changes in downstream demand
✓ Balanced piston and diaphragm design provides stable and repeatable back pressure regulation
✓ Direct-acting operation provides automatic pressure control without a separate external pilot system
✓ Precision piston and reinforced diaphragm provide fast response to changing system conditions
✓ UH-ring sealing helps minimise leakage and provides reliable long-term operation
✓ High flow capacity up to Cv 170 makes the RFF suitable for larger industrial process systems
✓ Stainless steel pressure gauge provides continuous indication of sustained upstream pressure
✓ Heavy-duty flanged construction provides secure integration into industrial process pipework
✓ 316 stainless steel construction provides excellent corrosion resistance for demanding water, chemical and process applications
✓ Factory pressure testing to 35 Bar provides additional assurance for long-term industrial service
Typical Applications
Industrial water systems
Reverse osmosis (RO) systems
Pure water installations
Water treatment plants
Chemical processing
Compressed air systems
Industrial gas systems
Food and beverage processing
Light oil systems
Pump and upstream equipment protection
Industrial process engineering
Applications requiring stable minimum upstream pressure
Manufacturing Quality
Manufactured from heavy-duty 316 stainless steel with precision-machined internal components, the Z-Tide Industrial RFF Series is engineered for reliable and repeatable upstream pressure regulation in demanding high-flow industrial applications.
The balanced piston and diaphragm design automatically maintains the selected back pressure despite changing downstream demand, while precision UH-ring sealing provides excellent sealing performance, rapid response and long service life.
Heavy-duty flanged construction provides robust integration into industrial process pipework, with 316L stainless steel welded flanges used from DN15 to DN50 and CF8M stainless steel flanges from DN65 to DN150. Each valve is factory pressure tested to 35 Bar for dependable long-term operation.
The supplied stainless steel pressure gauge provides continuous indication of sustained upstream pressure, simplifying commissioning, adjustment and routine system monitoring. Optional Duplex stainless steel construction, alternative flange standards, seal materials and pressure adjustment ranges are available for specialist applications.
Ordering Information
Simply select the required flange size, back pressure adjustment range and seal material before adding the valve to your basket.
Available sizes are DN15, DN20, DN25, DN32, DN40, DN50, DN65, DN80, DN100 and DN150 with PN16 flanges as standard.
Optional ANSI 150 lb, JIS10K or PN25 flange standards are available. NBR seals are standard, with FKM (Viton) or EPDM options available. Optional Duplex stainless steel construction and alternative pressure adjustment ranges are also available on request.
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