Watts LFM115-74-SA 4 Lead-Free Pressure Reducing Valve, Ductile Iron, Flanged

The Watts LFM115-74-SA 4 is a 4" lead-free globe-pattern pilot-operated pressure reducing control valve with Flanged connections. It features a ductile iron body and a epdm seat. Rated to 600 psi and up to 300°F. This model is certified lead-free for potable-water installations.

This 4 inch LFM115-74 ductile iron class 150 pressure reducing control valve with low flow by-pass is designed to automatically reduce a fluctuating higher upstream pressure to a constant lower downstream pressure regardless of varying flow rates. Flow requirements below the normal range of the main line pressure reducing control valve are handled by a separate, valve mounted, direct acting, low flow by-pass pressure reducing valve. A low flow by-pass Valve is piped parallel to the main pressure reducing valve and is set approximately 10 PSI higher. The low flow by-pass handles flow requirements below the range of the main pressure reducing valve. During off peak demand conditions, the low flow by-pass provides flow and pressure to the downstream zone. SentryPlus Alert® technology provides intelligent pressure monitoring and notifications using integrated sensors, and integrates with the Sensor Control Monitor to deliver maintenance alerts through BAS via RS-485 Modbus or the Nexa® platform over Wi-Fi.

Features

• Low Flow By-Pass Pressure Reducing Valve handles flow requirements below the normal range of the main line
• Automatically reduces a fluctuating higher upstream pressure to a constant lower downstream pressure
• Simplified and efficient design is easy and economical to maintain
• Integrates with the Sensor Control Monitor to deliver maintenance alerts to BAS via RS-485 Modbus or the Nexa platform by Wi-Fi connectivity
• Body and cover are constructed of strong and durable ductile iron - ASTM A536

Common Questions

What does the "-74" low-flow bypass do?

A large control valve cannot hold a stable outlet pressure at very low demand, so downstream pressure creeps up overnight. The -74 adds a small bypass regulator piped around the main valve that takes over at low flow and holds the setpoint, then hands back to the main valve as demand rises. It is the standard fix for night-time pressure creep on municipal and campus mains.

What is the maximum working pressure?

This unit is built as 150# Flanged and is rated to 600 psi. End connection sets the ceiling on this platform, and 150# and 300# bodies are not interchangeable — confirm the class matches your flange drilling before ordering.

What fluid temperature can the EPDM trim handle?

This valve is built with EPDM elastomers, good to about 300°F. Watts offers the same body with Buna-N (to 160°F), FKM/Viton (to 250°F) or EPDM (to 300°F) — pick the elastomer for your fluid temperature, not the body.

Is this valve UL Listed and FM Approved for fire protection?

Yes — this model carries the UL listing and FM approval required for fire-protection service. Non-listed control valves cannot be substituted on a fire job even when the body and pilot are otherwise identical.

Specifications

• Type: Pressure Regulator
• Size: 4"
• Inlet Size: 4"
• Outlet Size: 4"
• Connection: Flanged
• Body Material: Ductile Iron
• Seat / Seal Material: EPDM
• Pressure Class: Class 150
• Max Pressure (psi): 600
• Operation: Pilot-Operated Diaphragm
• Port Style: Full
• Country of Origin: United States
• Warranty: 1 Year Limited
• MPN: LFM115-74-SA 4
• Temperature: up to 300°F
• Certifications: ASSE-1003, UL, FM
• Lead-Free: Yes
• Item Type: Valve
• Control Function: Pressure Reducing (Low-Flow Bypass)
• Valve Platform: Mustang (M-Series)
• Body Pattern: Globe
• End Connection / Pressure Class: 150# Flanged
• Configured Options: Low-Flow Bypass;Bypass
• Coating: ArmorTek 3-Part Epoxy
• UL Listed / FM Approved: Yes