11.120.180 Equipment.
(a) Piping and Valves.
(1) A general arrangement of the required valves and piping is shown on Drawings DG-08-01, DG-08-01A, DG-08-01B, DG-08-02 and DG-08-02A. Reorientation and modification of this arrangement may be needed depending on site conditions, forcemain alignment, etc.
(2) The piping and fittings shall be cement mortar lined ductile iron. Pipe shall be joined by means of flanged connections.
(3) The swing check valve shall be of the outside lever and weight type. The valves for pump isolation and the valve on the discharge header downstream of the flowmeter shall be eccentric plug valves. The plug valves shall be oriented such that:
(i) The rotation of the plug is about a horizontal axis.
(ii) The plug stores at the top when the valve is open.
(iii) The seat is opposite the high pressure side (except for the plug valve on the bypass line).
(4) These criteria shall be clearly indicated on the contract drawings and also in the contract specifications.
(5) The bypass line back to the wetwell is for pump testing purposes and the “pump around” connection consisting of an elbow pointing up with a blind flange is for use in case of a complete failure of the pumping station.
(6) Acceptable Manufacturers.
(i) Swing check valves: American Flow Control, Apco-Willamette, GA Industries, Val-Matic.
(ii) Eccentric plug valves: DeZurik, Val-Matic, Victaulic (with flange end adapters only).
(b) Sump Pump. A close-coupled submersible sump pump with a capacity of 25 gpm and adequate TDH shall be provided in the sump. The pump shall be a Hydromatic model SD33 or a Goulds model ST31, rated for 120V AC single-phase operation and supplied with a three-conductor SO type cable and plug. Sump pump operation is to be controlled by a diaphragm switch.
The sump pump discharge shall be piped to the wetwell. The point of discharge shall be above the highest expected wetwell level, but below the platform level.
(c) Flow Meter. For all stations, a Venturi type or electromagnetic type flow meter as discussed under the section on flow metering shall be located inside the vault. (Design Guideline DG-08 § 6.3, dated August 2006)