16 Del. Admin. Code § 4464-6.0

Current through Register Vol. 28, No. 7, January 1, 2025

Section 4464-6.0 - Recirculation System - General Requirements

6.1 Recirculation system.

6.1.1 The recirculation system shall consist of, but is not limited to: a pump, a flow measuring device, a removable strainer with spare basket (not required on vacuum filters), a filter with at least one (1) pressure gauge, an automatic disinfectant feeder, piping, deep end floor outlet/drains, a perimeter overflow gutter or surface skimmers, return inlets, valves and other necessary equipment.

6.1.2 The recirculation system shall be designed to provide the maximum allowable turnover times:

6.1.2.1 Maximum Allowable Turnover Times

6.1.2.1.1 Swimming Pools maximum turnover 6 hours or less

6.1.2.1.2 Wading Pools maximum turnover 1 hour or less and shall have a secondary disinfection system

6.1.2.1.3 Spray Pads maximum turnover 1 hour or less and shall have a secondary disinfection system

6.1.2.1.4 Treatment pools maximum turnover 1 hour or less and shall have a secondary disinfection system

6.1.2.1.5 Spa Pool maximum turnover 15 minutes or less

6.1.3 In the pump/filter area, each suction and discharge line shall have a manual control valve capable of regulating flow or shutting off flow completely

6.1.3.1 If the required flow rate is provided collectively by multiple pumps, all of these pumps shall operate by a single control switch.

6.1.3.2 The difference between the minimum required flow rate in gallons per minute (gpm) (based on the type of pool) and the maximum allowable flow rate in gpm (based on the type of filtration) shall be at least ten (10) gpm.

6.2 Recirculation Pump

6.2.1 All recirculation pumps shall be of adequate capacity to provide the required turnover rate, a sufficient backwash rate and sufficient suction for any vacuum fittings.

6.2.2 If the pump or any suction side piping is located above the pool water level, the pump shall be self-priming.

6.2.3 All recirculation pumps shall be equipped with the necessary piping, valves etc. such that pool water can be pumped directly to waste.

6.2.3.1 This line shall terminate above any drain entry point by a distance of at least twice its diameter.

6.2.3.2 For the purpose of confirming or determining the flow rate, all recirculation pumps shall be equipped with pressure gauges on both the suction and pressure side the pump.

6.2.4 Rate of Flow Indicator

6.2.4.1 At least one (1) rate of flow indicator reading in gpm shall be installed after filtration on the pool return line.

6.2.4.2 The indicator shall be easily accessible for viewing, in proper working condition when the pool is open, sized such that the design flow rate is in the mid range of the indicator, and capable of measuring at least fifty (50) per cent more than the design flow rate.

6.2.4.3 The clearance upstream and downstream from the indicator shall comply with the manufacturer's specifications.

6.2.4.4 In lieu of the above, a pre-set flow control valve with a direct mounted meter kit and conversion chart may be used.

6.2.5 Floor Outlets/Drains

6.2.5.1 All pools shall be provided with at least two (2) floor outlets/drains at the deepest point which: are connected to the recirculation system through the same line; are at least six (6) feet apart at centers (for special designs, as far apart as possible or on different planes); are equipped with a flow control valve(s) near the recirculation pump; have an antivortex cover or a twelve inch by twelve inch (12" x 12") grate or larger; and can completely drain the pool.

6.2.5.2 All drain outlet pipes shall be recessed within the fitting or in a pit and equipped with a cover which can only be removed with a Phillips screwdriver or a special tool. The width and length of slot openings in the cover shall not exceed one half (1/2) inch and one (1) inch respectively.

6.2.6 Perimeter Overflow Gutters and Surface Skimmers

6.2.6.1 All pools shall have either perimeter overflow gutters or surface skimmers (not recommended for pools with a water surface area greater than 2500 square feet) which:

6.2.6.1.1 are capable of conducting one hundred (100) percent of the required flow rate;

6.2.6.1.2 are connected to the recirculation system; have flow control valves near the recirculation pump;

6.2.6.1.3 and effectively remove any floating material.

6.2.6.2 If perimeter overflow gutters are used, they shall be continuous around the pool with a uniform level rim which is not more than twelve (12) inches below the deck and which will provide a suitable handhold.

6.2.6.3 Gutters shall be designed so that the channel is easily accessible for cleaning and presents no entanglement hazard to bathers.

6.2.6.4 If the gutters are recessed, the access opening shall be at least four (4) inches.

6.2.6.5 Gutter drains shall be provided at uniform intervals not to exceed fifteen (15) feet and the gutter shall slope sufficiently to these drains.

6.2.6.6 The design shall ensure that the recirculation pump receive a continuous supply of water at all times either by adequate surge capacity within the gutters or a surge/balancing tank.

6.2.6.7 Any perimeter overflow gutter with a submerged protruding edge, shall have a solid marking line of contrasting color which is at least one (1) inch wide on the top surface edge of the gutter.

6.2.6.8 If surface skimmers are used, they shall be NSF listed and at least two (2) shall be provided.

6.2.6.8.1 For pools that are greater than one thousand (1000) square feet of water surface, one (1) additional skimmer shall be provided for each additional (500) square feet of pool water surface or fraction thereof.

6.2.6.8.2 Skimmers shall be optimally located around the pool perimeter and the recirculation system shall be designed such that the flow through each skimmer is at least twenty (20) gpm.

6.2.6.8.3 All skimmers shall have individual flow controls devices, an equalizer line (except WP pools), an easily removable, cleanable basket or screen and a cover.

6.2.7 Inlets

6.2.7.1 All pools shall have at least four (4) inlets, either on the side walls or on the floor, which are connected to the recirculation system.

6.2.7.1.1 Side wall inlets, with the exception of those built into a gutter, shall discharge at a depth of at least twelve (12) inches below the normal water level.

6.2.7.1.2 The distance between side wall or bottom inlets, measured along the wall or floor surface, shall not exceed twenty (20) feet and the spacing between any floor inlet and the side wall, measured along the surface, shall not exceed ten (10) feet.

6.2.7.1.3 When wall inlets are used, an inlet shall be provided within five (5) feet of each corner and one (1) in each recessed step area.

6.2.7.1.4 The inlets, either by adjustability or by design, shall provide the necessary flow to maintain the required disinfectant residual and chemical quality evenly throughout the pool.

6.2.8 Vacuuming

6.2.8.1 All pools shall have the capability of vacuuming the bottom either through a skimmer, a separate vacuum fitting or a portable vacuum system.

6.2.8.1.1 If a portable vacuum system must be used, it shall be stored on-site when the pool is open.

6.2.8.1.1.1 Vacuuming through a portable vacuum system that is connected to the potable water supply shall be prohibited.

6.2.8.1.1.2 In line and portable vacuum pumps must be equipped with a removable strainer with a spare basket.

6.2.9 Piping

6.2.9.1 Recirculation system piping shall be made of non-toxic material.

6.2.9.2 All plastic piping shall be: labeled with the manufacturer's name and the NSF logo for potable water; listed in the current NSF "Listing of Plastic Materials, Pipe, Fittings, and Appurtenances for Potable Water and Wastewater, or approved equivalent;" and used/installed in accordance with the manufacturer's specifications.

6.2.10 Multiport Valves

6.2.10.1 All multiport valves shall be NSF listed.

6.2.11 Pool Water Heaters

6.2.11.1 All gas heaters shall be design-certified by the American Gas Association (AGA) and shall display a rating data plate and the AGA seal.

6.2.11.2 All electric heaters shall be Underwriters Laboratories (UL) approved and shall display the UL seal.

6.2.11.3 All heaters shall have sufficient piping and valves to permit isolation and removal of the heater from the system.

6.2.12 Equipment Access, Freezing Protection and Drainage

6.2.12.1 Easy access shall be provided to all parts of the recirculation system that must be inspected or serviced.

6.2.12.2 All piping and equipment that is subject to freezing shall be provided with an adequate means of draining.

6.2.12.3 At least thirty (30) foot candles of illumination shall be provided around all equipment.

6.2.12.4 In order to prevent standing water, all equipment rooms shall be adequately graded toward floor drains or areas where the water will have a free unobstructed flow to points of disposal.

16 Del. Admin. Code § 4464-6.0

19 DE Reg. 309( 10/1/2015) (Final)