Watts M1115-2 - Manual (Page 8)

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Specifications
M115-2 (Globe)
M1115-2 (Angle)
The Pressure Reducing and Sustaining Control Valve shall be a pilot operated diaphragm valve designed
to automatically reduce a fluctuating higher upstream pressure to a constant lower downstream pressure
regardless of varying flow rates, and sustain a minimum upstream pressure.
The main valve shall be a hydraulically operated, single diaphragm actuated, globe or angle pattern valve.
Y-pattern valves shall not be permitted. The valve shall contain a disc and diaphragm assembly that forms
a sealed chamber below the valve cover, separating operating pressure from line pressure. The diaphragm
shall be constructed of nylon reinforced Buna-N, and shall not seal directly against the valve seat and shall
be fully supported by the valve body and cover. Rolling diaphragm construction will not be allowed and
there shall be no pistons operating the main valve or any pilot controls.
The main valve body and cover shall be Ductile Iron ASTM A536, and all internal cast components shall
be Ductile Iron or CF8M (316) Stainless Steel. All Ductile Iron components, including the body and cover,
shall be lined and coated with an NSF 61 Certified Epoxy Coating applied by the electrostatic heat fusion
process. All main valve trim and throttling components (cover bearing, valve seat and disc guide) shall
be Stainless Steel. The valve body and cover must be machined with a 360-degree locating lip to assure
proper alignment.
The disc and diaphragm assembly shall contain a Buna-N synthetic rubber disc with a rectangular cross-
section that is securely retained on 3-1/2 sides by a disc retainer and disc guide. Diaphragm assemblies
utilizing bolts or cap screws for component retention will not be permitted.
The exposed portion of the seat disc shall contact the valve seat and seal drip-tight. The disc and diaphragm
assembly must be guided by two separate bearings, one installed in the valve cover and one concentrically
located within the valve seat, to avoid deflection and assure positive disc-to-seat contact. Center guided
valves will not be permitted. All necessary repairs shall be made from the top of the valve while the body
remains in line.
Pilot control systems for valves 3” and smaller shall contain a Flow Clean Strainer, Fixed Orifice Closing
Speed, Adjustable Opening Speed Control, Pressure Sustaining Pilot and Pressure Reducing Pilot. Pilot
control systems for valves 4” and larger shall contain an external Y-Strainer, Fixed Orifice Closing Speed,
Pressure Sustaining Pilot, Pressure Reducing Pilot and Isolation Ball Valves on all body connections. All
pilot control systems shall utilize copper tubing and brass fittings regardless of valve size. The adjustment
range of the pressure sustaining pilot shall be 20-200 psi and the pressure reducing pilot shall be 30-300
psi.
The valve shall be Watts ACV Model M115-2 or M6115-2 (Globe) or M1115-2 or M61115-2 (Angle) pattern
Pressure Reducing and Sustaining Control Valve.
Other Watts ACV Pressure Reducing Control Valves
M115 / M6115 Pressure Reducing Valve
M115-3 / M6115-3 Pressure Reducing Valve with Hydraulic Check Feature
M115-4 / M6115-4 Pressure Reducing Valve with Solenoid (On-Off) Feature
M115-7 / M6115-7 Pressure Reducing Valve with Downstream Surge Control Feature
M115-11 / M6115-11 Pressure Reducing and Sustaining Valve with Hydraulic Check Feature
M115-43 / M1115-43 Pressure Reducing and Sustaining Valve with Surge Control Feature
M115-58 / M6115-58 Pressure Reducing Valve with Return Flow Feature
M115-74 / M6115-74 Pressure Reducing Valve with Low Flow By-Pass
910 Ops & Inst