Section 15105 CHECK VALVES

Section 15105

CHECK VALVES

PART 1 – GENERAL

1.1 THE REQUIREMENT

A. The work of this Section includes providing check valves with epoxy coating, operators, and accessories.

1.2 REFERENCE SPECIFICATIONS, CODES AND STANDARDS

A. Comply with the reference specifications of Sections 01090, 09800, 15100 and 15101. B. Comply with the current provisions of the following Codes and Standards.

1. Commercial Standards

	ASTM A126	Gray Iron Castings for Valves, Flanges, and Pipe Fittings
	ASTM B62	Composition Bronze or Ounce Metal Castings
	ASTM B148	Aluminum-Bronze Sand Castings
	AWWA C508	Swing-Check Valves for Waterworks Service, 2-In. through
1.3	QUALITY ASSURANCE	24 In.

A. Valves shall be tested in compliance with AWWA C506, AWWAC508 and Section 15100.

PART 2 – PRODUCTS

2.1 SWING CHECK VALVES (3-INCH AND LARGER)

A. General: Except as otherwise indicated, swing check valves designed for water, sewage, sludge, and general service shall be of the outside lever and weight in accordance with AWWA C508, full-opening; suitable for operation for either horizontal or vertical position, designed for a minimum working pressure of 150 psi and shall have a flanged cover piece to provide access to the disc. Valves shall be designed to accommodate dashpots or air cushion cylinders.

B. Coating: Corrosive ferrous surfaces of valves which will be in contact with water

(exclusive of flange faces) shall be epoxy coated complying with Section 09800.

C. Body: The valve body and cover shall be fabricated with cast iron conforming to ASTM A126, with flanged ends conforming to ANSI B16.1 or mechanical joint ends, as indicated.

D. Disc: The valve disc shall be fabricated of cast iron, ductile iron, or bronze conforming to

ASTM B62.

E. Seat and Rings: The valve seat and rings shall be fabricated of bronze conforming to

ASTM B62 or ASTM B148.

F. Hinge Pin: The hinge pin shall be of stainless steel and keyed to the hinge.

G. Limit Switches: Swing check valves on the primary sedimentation tank drain pumps check valves have limit switches with necessary contacts for pump status indication as shown in the instrumentation drawings.

H. Manufacturers:

Swing check valves shall be manufactured by one of the following or equal:

1. Apco Willamette Valve & Primer Corporation

2. GA Industries, Inc.

3. Kennedy Valve

2.2 DOUBLE-DISC CHECK VALVES

A. General: Double-leaf check valves intended for air and gas service and where indicated, shall be of the wafer-type designed to fit between ANSI B16.1 flanges rated at 125-lb. The check valve leaves shall be spring-loaded. Flow from one direction shall cause the valve to open, and upon valve shutoff, the spring shall shut the valve leaves before reverse flow starts and at a point of zero velocity, with non-slam closure. The spring- tension of each valve shall be designed for the individual operating condition.

B. Body: The valve body shall be fabricated of cast iron with integrally-cast seat, rated for minimum 300-lb test pressure at up to 250 degrees F.

C. Discs: Unless otherwise specified, discs or plates shall be aluminum bronze. Discs on valves used for sludge gas (Piping System 4/4A) shall be stainless steel.

D. Seat: The valves shall have resilient seats designed for bubble-tight shut-off suitable for temperatures up to 250 degrees F without sticking. The seats shall be Buna-N, Viton, or other material suitable for the intended purpose. The seat rings shall be firmly attached to the body or disc by compression-molding or proper method.

E. Springs: The springs shall be of Type 316 stainless steel, or Inconel and recommended by the manufacturer for use in the service indicated.

F. Manufacturers:

Double disc check valves shall be manufactured by one of the following or equal:

1. Apco Willamette Valve & Primer Corporation

2. TRW Mission Manufacturing Company

2.3 RUBBER FLAPPER SWING CHECK VALVE

A. Rubber flap swing check valves shall are intended for service for digested sludge application on the discharge of the Sludge Mixing Pumps at Digester No. 2.

B. The Rubber flapper swing check valve shall have a heavily constructed cast iron body and cover. The body shall be long pattern design (not Wafer), with integrally cast-on end flanges. The flapper shall be Buna-N having a "0" ring seating edge and be internally reinforced with steel.

C. Flapper to be captured between the body and the body cover in a manner to permit the flapper to flex from closed to full open position during flow through the valve. Flapper shall be easily removed without need to remove the valve from the line. Check valve to have full pipe size flow area. Seating surface to be on a 45° angle requiring the flapper to travel only 35° from closed to full open position, for minimum head loss and non-slam closure.

D. Buna-N flapper (70 Duro) creates an elastic spring effect to assist the flapper to close against a slight head to prevent slamming.

E. Valve designed for 175 psi working pressure for water. The Valve shall be suitable for buried service with stainless cover bolts.

F. Valve exterior to factory primed in accordance with the requirements of Section 09800, Protective Coating.

G. The Valve Manufacturer shall have been regularly engaged in the design and manufacture of rubber flapper check valves for at least five years and shall submit a list of at least five separate installations in service for a minimum of five years for engineer approval prior to release to manufacture.

H. Materials of construction shall be certified in writing to conform to ASTM. specifications as follows:

1. Body and Cover: Cast Iron, ASTMA126 Gr. B or Ductile Iron ASTM A536

2. Rubber Flapper: Buna-N I. Manufacturers:

Rubber flapper swing check valves shall be manufactured by one of the following or equal:

1. Apco Willamette Valve & Primer Corporation

2. GA Industries, Inc.

2.4 SWING CHECK VALVES (2-1/2-INCH AND SMALLER)

A. General: Swing check valves for steam, water, oil, or gas in sizes 2-1/2-inch and smaller shall be Y-pattern, suitable for a steam pressure of 200 psi and a cold water pressure of

300 psi. They shall have screwed ends, unless otherwise shown, and screwed caps.

B. Body: The valve body and cap shall be of bronze conforming to ASTM B 61 and with threaded ends conforming to ANSI/ASME B1.20.1.

C. Disc: Valves for steam service shall have bronze discs, and for cold water, oil, and gas service replaceable composition discs.

D. Hinge Pin: The hinge pins shall be of stainless steel.

E. Swing check valves shall be manufactured by one of the following or equal:

1. Crane

2. Stockham

3. Milwaukee Valve

2.5 PLASTIC SWING CHECK VALVES

A. General: Plastic swing check valves for corrosive fluids, in sizes up to 8 inches, may be used for horizontal or vertical upflow conditions.

B. Construction: The valve bodies and discs shall be of PP, or PVDF construction, as best suited for each individual service condition. They shall have flanged ends conforming to ANSI B16.5, class 150, and flanged top access covers, and they shall shut positively at no-flow conditions. The seats and seals shall be of EPDM, Teflon, or Viton. The valves shall be rated for a maximum non-shock working pressure of 150 psi at 73 degrees F for sizes 3-inch and smaller. For larger sizes and other materials and temperatures the pressure rating will be lower.

C. Plastic swing check valves shall be manufactured by one of the following or equal:

1. Asahi-America

2. Harrington Plastics

PART 3 – EXECUTION

3.1 INSTALLATION

A. Installation shall be in accordance with the manufacturer’s instructions and Section

15100.

END OF SECTION