Watts S1118-3 User Manual

R

NON-SURGE CHECK VALVE

(4” and Smaller)

01/05

Stainless Series

S1118-3 or S61118-3 (Angle)

Specifications

The Non-Surge Check Valve shall be a diaphragm control valve designed to control pipeline surges caused
by flow reversal by slowly opening and closing at separate adjustable rates.

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 shall be fabricated 304L with Class D zinc plated steel flanges, utilizing stainless
steel seal welds allowing the entire flow path to be stainless steel. External steel components shall be fully
primed and painted with a stainless steel paint to prevent surface corrosion. The valve cover and all internal
components shall be fabricated 304L Stainless Steel, and the main valve trim and throttling components
(cover bearing, valve seat and disc guide) shall be Stainless Steel.

The disc and diaphragm assembly shall contain a Buna-N synthetic rubber disc with a rectangular cross­section 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.

S118-3 or S6118-3 (Globe)

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 shall contain (2) Check Valves, separate Adjustable Opening and Closing Speed
Controls and Isolation Ball Valves on all body connections. The pilot control system shall utilize copper
tubing and brass fittings.

The valve shall be Watts ACV Model S118-3 / S6118-3 (Globe) or Model S1118-3 / S61118-3 (Angle) Non­Surge Check Valve.

8550 Hansen Road • Houston, Texas 77075 • (Ph) 713.943.0688 • (Fx) 713.944.9445 • www.wattsacv.com