12 Va. Admin. Code § 5-590-1050

Current through Register Vol. 40, No. 22, June 17, 2024

Section 12VAC5-590-1050 - Pumps and controls

A. General.

1. Pumps, pump motors, and all accessories shall be controlled in a manner that they will operate at their rated capacity. Where two or more pumps are installed, provision shall be made for proper alternation of the pumps. Alternation may be automatic or manual. Provision shall be made to prevent operation of the pump in the event of a backspin cycle.

2. All pumps shall be driven by motors designed to operate over the full range of operating conditions.

3. All pumps shall be served by control equipment that has overload protection for the air temperature encountered.

4. Electrical controls shall be protected to the 100-year flood elevation and should be located above grade.

5. If standby power is provided by onsite generators or engines, then the provisions for filling the fuel storage tank, the fuel tank itself, and the fuel line shall be designed to protect the waterworks and source water from contamination.

6. Pumps shall be lubricated with water of equal or better quality than the water being pumped or with food grade oil. Water seals shall not be supplied with water of a lesser sanitary quality than that of the water being pumped. Where pumps are sealed with potable water and are pumping water of lesser sanitary quality, the seal shall:

a. Have an air gap of at least two inches or two pipe diameters, whichever is greater, where a break-tank is provided; or

b. Be provided with an approved RPZ assembly.

7. When automatic pre-lubrication of pump bearings is necessary and an auxiliary power supply is provided, the pre-lubrication line shall be provided with a valved bypass around the automatic control.

8. A suitable outlet for drainage from pump glands shall be provided without discharging onto the floor.

B. Booster pumps.

1. Booster pumps, except those connected to supply mains not containing service connections and except those taking suction directly from storage facilities, shall be located or controlled so that:

a. They will not produce negative gauge pressure in their suction line; and

b. The intake pressure shall be at least 20 psi when the pump is in normal operation.

2. An automatic pressure cutoff or a pressure-regulating valve shall be provided to prevent the suction line pressure from dropping to below 10 psi.

3. Automatic or remote control devices shall have sufficient range between the start and cutoff pressure, or another mechanism that will prevent excessive cycling of the pumps.

4. At least two pumping units shall be provided.

a. If only two units are provided, then each shall be capable of delivering the peak hour demand, taking into account storage contributions.

b. If more than two units are installed, then they shall have sufficient capacity so that if any one pump is out of service, the remaining pumps are capable of meeting the peak hour demand, taking into account storage contributions.

c. When using booster pumps to transfer water from atmospheric storage tanks to hydropneumatic tanks located upstream of an entry point into the distribution system, the combined capacity of the two pumps shall equal or exceed the peak hour demand. If fire flow is provided, then a pump separate from the transfer pumps shall be provided to deliver the required fire flow.

d. When booster pumping is required for small noncommunity systems, the reserve capacity requirements may be reduced in accordance with the type and size of system served.

5. Controls shall be provided to shut off pumps in the event that suction conditions may result in cavitation.

12 Va. Admin. Code § 5-590-1050

Derived from VR355-18-010.05 § 3.42, eff. August 1, 1991; Amended, Virginia Register Volume 37, Issue 20, eff. 6/23/2021.

Statutory Authority: §§ 32.1-12 and 32.1-170 of the Code of Virginia.