(A) Acceptable manufacturers. Pumps shall be as manufactured by Hydromatic Pumps, Inc. of Ashland, Ohio; Barnes Pumps, Inc of Piqua, Ohio, or equal.
(B) Materials.
(1) Submersible non-clog pumps.
(a) The pumps shall be four inches or six inches vertical, non-clog type of heavy cast iron construction, designed for the use of mechanical seals. The pump casing and volute shall be made of ASTM A48 Class 30 cast iron. The volute shall have smooth fluid passages capable of passing a three-inch minimum solid sphere. The pump casing shall include large clean out openings for access to the volute and impeller. The casing shall be arranged so that the impeller can be removed without disturbing the suction and discharge piping. The casing suction and discharge heads shall be connected to the piping with standard 125-pound ANSI flanges.
(b) The pump casing shall include three-fourths-inch taps for discharge pressure gauge connection and pump volute drain.
(c) The pump shall be mounted on a pump pad and cast iron frame as required to meet the arrangement shown on the drawings. The motor shall be attached to the pump volute by a one-piece cast iron adapter and backhead. The pump shall be arranged so that the rotating element can easily be removed from the volute without disconnecting the seal system or electrical wiring. The pump shall be arranged so that any foreign object may be removed from the pump or suction elbow without disassembling the motor, impeller or backhead.
(d) The pump impeller shall be of the single-suction, enclosed, two vane type made of ASTM A48 cast iron and shall be properly balanced. The impeller shall be keyed with a stainless steel key and secured to the motor shaft by a stainless steel cap screw equipped with a self-locking device. The impeller shall be keyed and bolted to the pump shaft and shall be readily removable without the use of special tools. To prevent the buildup of stringy materials, grit and other foreign particles around the pump shaft, all impellers less than full diameter shall be trimmed inside the impeller shroud. The shroud shall remain full diameter so that close minimum clearance from shroud to volute is maintained.
(e) The shaft shall be solid steel through the mechanical seal to eliminate corrosion and abrasive rust particles. The shaft shall be accurately machined and tapered at the impeller end. Renewable stainless steel shaft sleeves shall be provided to prevent leakage and shall extend the full length of the seal housing and under the gland.
(f) The pump shaft shall be sealed against leakage by a double mechanical seal installed in a bronze seal housing constructed in two sections. The housing shall be recessed into the pump backhead and securely fastened thereto.
(g) The seal shall be pressurized and lubricated by water from an outside potable water source. The water shall pass through a filter to the seal housing and be introduced between the upper and lower sealing surfaces. The seal system shall contain a brass valve connected near the top of the seal housing to permit the relief of any air trapped in the seal unit.
(h) The pump bearing frame shall be one-piece cast iron construction consisting of a cast iron bearing housing at the outboard end and a cast iron end cover at the inboard end. The radial inboard bearing shall be single row, roller type suitable for all loads encountered in the service condition. Axial thrust outboard bearings shall be angular contact, double row ball type suitable for thrust loads in two directions. Bearings shall be grease lubricated and designed for a minimum L10 life of 100,000 hours per AFBMA.
(2) Lift station control panel.
(a) General.
1. The pump manufacturer shall furnish an automatic pump station controller for operation on a three-phase, 60 hertz power source.
2. The pump station controller shall be suitable for operation and automatic alternation of a duplex pump system and shall be complete with motor control, solid state alternator, convenience power supply, miscellaneous controls and the like. All components shall be UL listed.
3. Controls for each of the two pumps shall be rated for the actual horsepower from the manufacturer’s information.
4. The control and power wiring for the pumps and level sensors shall be arranged to extend through two separate conduits to the wetwell. Conduits shall be properly sealed to protect the panel against explosive type gases which may exist in the wetwell.
(b) Panel enclosure.
1. The enclosure shall be NEMA 4X with drip shield, 14-gauge stainless steel (minimum), welded construction. The enclosure shall have an outer weather door, a hinged inner “operator’s door” and mounting hardware.
2. All equipment, controls and the like shall be located inside the enclosure. Selector switches, pilot lights and the like shall be located on a deadfront swingout panel (operator’s door) located behind an outside weather door. All other equipment, exposed wiring and the like shall be located behind the swingout panel.
(c) Controller features; operating sequence.
1. a. When a pump is called for by the water level in the wet well, the control unit shall send a start signal to the appropriate pump and verify operation with the starter auxiliary contact. Appropriate verification time delays shall be included.
b. When the wet well level continues to rise, the second pump shall start.
c. When the wet well level reaches low level, the pump(s) shall stop and pump alternation shall occur.
d. When the pump run verification signal is not received with the appropriate time period, the alternator shall deselect the failed pump, select the next pump, remove the failed pump from the sequence, illuminate a pump fail light. The failed pump shall remain out of service and the pump fail light shall remain illuminated until manually reset.
2. Terminal blocks for incoming power, pump power conductors, level sensors, leak detectors, motor thermal sensors and control wiring.
3. Circuit breakers with over-current protection for each of two pumps and the convenience power transformer. Circuit breakers shall be magnetic-hydraulic or thermal magnetic, ambient temperature compensated type, calibrated and factory sealed with the proper trip setting. The devices shall have a minimum interrupting rating of 10,000 RMS symmetrical.
4. Magnetic full voltage starters for each of two pumps. The starter overload relays (one per phase) shall be ambient compensated, quick-trip type. Overload elements shall be matched to the pump motor characteristics.
5. Convenience and control power transformer with 460-volt primary and 120/240 volt secondary rated at 2KW (where required due to three phase service).
6. Convenience power distribution panel (30A, 120/240V, 1PH-3W) with main breaker and 20A, 1P branches. Circuit breaker operators shall be accessible without opening the deadfront “operator’s door”. Branch breakers shall be supplied as follows: one for control; one for GFI receptacle; and one for condensate heater.
7. GFI type duplex convenience receptacle (120V, 20A) mounted on the dead front operator’s door.
8. A low volt power supply and interface system suitable for operation of the float switches in an intrinsically (explosion proof) safe mode.
9. An adjustable thermostatically controlled heater to provide condensate protection inside the enclosure.
10. Two pump automatic electronic alternator which will alternate the pumps with each pump down cycle.
11. The pump controller shall provide relay outputs to interface with the motor control devices as required.
12. Running time meters for each pump. The meter shall indicate the number of hours of pump operation. The meter shall be enclosed in a dust and moisture proof molded plastic case. The flush mounted dial shall register in hours and tenths of hours up to 999.9 hours before repeating.
13. a. The control panel shall provide the following status/alarm indications for each pump:
i. Pump running light (green);
ii. Pump failed light (red);
iii. Seal failure; and
iv. High wet well level.
b. In addition, the panel shall have a Hand-Off-Auto selector switch for each pump to control mode of pump operation and timing modules as required for the pump failed feature.
14. The local alarm system shall consist of an alarm light and shall signal any of the above alarm conditions.
15. The alarm light shall be a weatherproof high intensity strobe fixture with a red lexan globe and a metal globe guard mounted on top of the enclosure.
(d) Level sensors.
1. The level sensors shall consist of weighted floats with mercury contacts rated for low volt operation at milliwatt levels. Each level sensor shall be furnished complete with sufficient cable length to run to the terminal box below the pump station controller and leave slack for future level adjustment.
2. Floats shall meet the requirements for Class 1, Division 1, Group C and D and be intrinsically safe for installation in an explosion hazard environment.
3. Floats shall operate at a maximum of 24 volts.
4. Furnish a stainless steel bracket mounted in the hatch opening for hanging the sensor cables.
(C) Lift station piping.
(1) Interior lift station and valve pit piping shall be flanged ductile iron, centrifugally cast conforming to the latest revisions of ANSI/AWWA C150/A21.50 and ANSI/AWWA C151/A21.51. The interior surface of the pipe shall be cement lined and seal coated in accordance with ANSI/AWWA C104/A21.4. Pipe shall be Pressure Class 250 minimum.
(2) Flanges shall be of 250 psi working pressured, drilled to ASA 125 pounds standards and meeting the requirements of ANSI/AWWA C111/21.10.
(D) Valves.
(1) General.
(a) All valves shall be furnished with an exterior finish coating the same as the adjacent piping system to which they are connected or as approved by the town.
(b) All valves of the same type shall be by the same manufacturer.
(c) Where required for satisfactory operation of valves, provide extension stems, stem guides, cast iron valve and curb boxes, floor boxes and other valve appurtenances. Extension stems shall be complete with guide bearings, wrench nut and tee handle wrench. All valve stems and machinery stuffing boxes shall be packed with material as selected for the intended service. All valves shall be designed for repacking.
(d) Tee wrench operators shall be provided as required for proper operation.
(2) Plug valves.
(a) Plug valves shall be of the non-lubricated, resilient seated, eccentric type.
(b) All plug valves shall be of the size indicated on the drawings. All plug valves shall be of the drip-tight-closing, resilient-faced plug type and shall be of the eccentric seating construction such that the opening movement of the closing member (plug) results in the closing member rising off the body seat contact. Port areas shall be equal to at least 80% of the nominal size pipe area.
(c) Valve bodies, bonnets and plugs shall be constructed of cast iron meeting the requirements of ASTM A126 Class B.
(d) Valves shall be rated for 175 psi up to 12 inches and 150 psi for valves 14 inches and larger. An adjustable close position stop shall be provided for field adjustment. The seat end and standard flow direction shall be cast on the valve body.
(e) All shaft seals shall be replaceable without disassembling the valve and while the valve is under system operating pressure.
(f) The plug shall be of a one piece design with a precision molded resilient facing. The resilient seating surface shall not be in the flow way pattern when the valve is in the open position. The body seating surface shall be welded nickel overlay containing a minimum of 90% nickel.
(g) Radial journal bearings shall be stainless steel, of the permanently lubricated type. Two thrust bearings shall be provided in the upper journal area, one of stainless steel and one of Teflon. The lower journal shall have one stainless steel thrust bearing of the non-adjustable type. Grit seals shall be furnished in the upper and lower journals to prevent abrasive media from entering the bearing and seal areas.
(h) Unless otherwise noted or shown, all valve and connections shall be ANSI Class 125 flanges.
(i) Valve shall be series 5000 as manufactured by Val-Matic Valve and Mfg. Corp., Series 100, as manufactured by Dezurik, or equal.
(3) Rubber flapper swing check valves.
(a) Swing check valves shall have a cast iron body and cover meeting the requirements of ASTM A126, Class B. The valve body shall have full flow equal to the nominal pipe diameter at any point through the valve. Valve shall be designed for a 175-psi minimum working pressure.
(b) The valve seating surface shall be on a 45-degree angle to minimize disc travel. The disc shall be of one piece construction, precision molded with an integral O-ring type sealing surface. The disc shall be made of Buna-N and have a non-slam closing characteristic by means of a 35-degree disc stroke and disc return action.
(c) The top access port shall be full size, allowing removal of the disc without removing the valve from the pipeline.
(d) The check valve shall have backflow capabilities by means of a screw type backflow actuator.
(e) The interior of the valve shall be coated with an epoxy suitable for potable water.
(f) Unless otherwise shown or noted, the check valves end sections shall be ANSI Class 125 flanges.
(g) Rubber flapper swing check valves shall be as manufactured by Val-Matic Valve and Manufacturing Corp., or equal.
(4) Mud valves. Valves shall be of spigot end, non-rising steam design having a cast iron body. The stem, stem nut, seat ring and disc ring shall be made of bronze. All bolts and nuts shall be of corrosion resistant steel. Valves shall be furnished complete with extension steam having a two-inch square not as required for the application. Each valve to be furnished with a tee handle wrench of length as required by the drawings. Mud valves shall be Model F-3080 as manufactured by Clow, or equal.
(2004 Code, Art. II, § D, part 2)