Flanged x Grooved Pressure Reducing Valve

The Fluid Tech Flanged x Grooved Pressure Reducing Valve (PRV) is a high-precision, hydraulically operated automatic control valve designed to reduce high upstream inlet pressure to a stable, pre-set downstream outlet pressure, regardless of flow rate fluctuations or varying inlet pressures.

Featuring a hybrid Flanged End x Grooved End connection, this valve offers superior installation flexibility. The flanged connection seamlessly integrates with standard flanged equipment, main pumps, or isolation valves, while the grooved end allows for rapid, vibration-damping connection to standard grooved piping systems.

Engineered from heavy-duty ductile iron (QT450-10 / ASTM A536) and coated with fusion-bonded epoxy, Fluid Tech Fire Protection Pressure Reducing Valve deliver exceptionally low friction loss, precise pilot control, and long-term cavitation resistance. They are widely used in fire sprinkler networks, commercial HVAC systems, high-rise building water supply networks, and industrial liquid pipelines.

Key Features & Benefits

Feature	Benefit
Pilot-Operated Regulation	Constant outlet pressure across entire flow range — no droop, no fall-off
UL 1739 Listed	Code-compliant for automatic fire sprinkler systems per NFPA standards
Single-Screw Pressure Adjustment	Quick, tool-free set point changes — saves commissioning time
Adjustable Response Speed	Tune opening/closing speed to match system characteristics; prevents water hammer
Near-Zero Flow Stability	Maintains regulation even at dead-end conditions (no minimum flow required)
FLG×GRV Hybrid Ends	Flanged inlet for rigid pump-room connections; grooved outlet for rapid field assembly
Dual Coating Options	Enamel paint or Fusion Bonded Epoxy — choose based on environment and budget
Wide Downstream Range	Three spring ranges cover 15 psi to 165 psi (1.0 bar to 11.4 bar) outlet pressure
Ductile Iron Body & Bonnet	ASTM A536 Grade 65-45-12 — 3× the strength of grey cast iron
Stainless Steel Trim	Seat, stem, and spring in ASTM A276 Type 304 for long service life

Material Specifications

Part	Material	ASTM Specification
Body	Ductile Iron	A536 Grade 65-45-12
Bonnet	Ductile Iron	A536 Grade 65-45-12
Seat	Stainless Steel	A276 Type 304
Stem	Stainless Steel	A276 Type 304
Spring	Stainless Steel	A276 Type 304
Diaphragm	Nylon Reinforced Natural Rubber / EPDM / NBR	—
Seat Disc	NBR / EPDM	—
Pressure Reducing Pilot	Bronze	ASTM B62 C62300

Pilot Assembly Components

 

No.	Component	Function
1	Basic Control Valve	Main flow path and pressure chamber
2	Pressure Reducing Pilot	Senses downstream pressure and modulates main valve
3	Ejector	Creates pressure differential for pilot operation
4	Y-Strainer	Protects pilot circuit from debris
5	Tubing / Fittings	Interconnects pilot circuit components
6	Stabilizer	Dampens oscillations for stable regulation

 

Main Dimensions (mm / inch)

DN Size	40	50	65	80	100	125	150	200	250	300
L (mm)	210	241	265	292	330	356	432	533	635	762
L (inch)	8.26	9.48	10.45	11.5	13.0	14.0	17.0	21.0	25.0	30.0
H (mm)	180	200	215	265	290	340	390	470	570	690
H (inch)	7.1	7.9	8.46	10.45	11.42	13.4	15.35	18.5	22.45	27.2
W (mm)	410	420	440	455	455	470	490	540	590	640
W (inch)	16.2	16.6	17.35	18.0	18.0	18.5	19.3	21.25	23.23	25.2

Applications

• Fire Sprinkler Systems — Maintains optimal sprinkler operating pressure (UL 1739 approved)
• High-Rise Building Water Supply — Zone pressure control for multi-level distribution
• Municipal Water Networks — Reduces transmission main pressure to distribution-level pressure
• Industrial Process Water — Precise pressure control for cooling circuits and process lines
• Irrigation Systems — Consistent pressure for uniform spray coverage
• Plumbing & HVAC — Boiler feed, cooling tower make-up, and domestic water pressure regulation

Why Choose WEFLO FIG. F1318?

1. UL 1739 Certification — Recognized by fire protection valve authorities globally; simplifies approval with local AHJs.
2. FLG×GRV Flexibility — The hybrid end configuration is ideal for mechanical rooms where you need a rigid flanged inlet but prefer grooved field connections for faster installation downstream.
3. Zero Minimum Flow — Unlike many competitors, the F1318 regulates accurately even at dead-end or near-zero flow — no bypass valve needed.
4. Pilot Serviceability — The bronze pilot assembly is designed for easy field maintenance without removing the main valve from the line.
5. Three Spring Ranges — One valve platform covers 90% of commercial and industrial pressure reducing applications.

Flanged x Grooved Pressure Reducing Valve FAQ

Q1: What are the main advantages of a Flanged x Grooved (FLG × GRV) connection?

The hybrid FLG × GRV design combines the structural rigidity of a flanged connection with the rapid, vibration-damping installation of a grooved joint. It allows direct coupling to flanged equipment (such as pumps, check valves, or main headers) on the inlet side, while seamlessly connecting to grooved distribution piping on the outlet side. This eliminates extra adaptors or spool pieces, reducing total installation time, labor costs, and potential leak paths.

Q2: How does this pilot-operated pressure reducing valve maintain constant outlet pressure?

The valve uses a sensitive, stainless-steel pilot control system that continuously monitors downstream pressure. When downstream demand fluctuates, the pilot automatically adjusts water pressure inside the main valve diaphragm chamber. This throttles or opens the main valve to lock in the preset downstream pressure—delivering precise pressure regulation from near-zero trickle flow up to maximum rated capacity.

Q3: Is this valve suitable for fire protection systems?

Yes. Designed in compliance with UL 1739 / NFPA 13 & 14 standards, our Flanged x Grooved PRVs are widely used in fire sprinkler risers, standpipe systems, and deluge networks to protect sprinkler heads and hose connections from excessive line pressures. (Submittal sheets and UL/FM certificate documentation are available upon request).