HOW TO WRITE YOUR SPECIFICATIONS
Complete information on how to fully write pool specifications! This is quite a read, so there’s a lot of content to digest! Don’t get overwhelmed, we have broken it up into the sections relevant you may be writing specifications for. We encourage you to use the Find function of your browser to skip to the relevant product you’re writing specifications for.
AUTOMATIC SKIMMER (Pentair / StaRite)
The Skimmer (s) are a device that causes surface water to be drawn into an opening through a molded durable, non-corrosive ABS plastic canister. This device is pre-fabricated by the manufacturer and as such during the installation process it is encapsulated by the swimming pool steel reinforcement skeleton and positioned in a fashion that allows the top of the canister through a throated opening to correspond with the correct level of water line tile and decking elevations. The interior of the Skimmer has a leaf trap basket that is designed to capture and contain floating debris from the pool water surface as water is drawn from the surface and flows through the basket on it’s journey to the pump inlet. Located at the bottom of the Skimmer are two pipe connections, the front connection is plumbed to an equalizer line that returns to the pool and together with an Equalizer Float Assembly and Equalizer Valve positioned at the bottom of the Skimmer device providing low water level protection. This inlet port of the equalizer line is covered with an Anti-Vortex Lid Covers at the finish plaster stage. The rear connection is connected to a dedicated suction line (See Pipe Sizing) which runs to the pump inlet. This connection can facilitate a vacuum hose during manual maintenance procedures by inserting the hose and connecting that to a vacuum head and a telescopic pole (See Isolation Valves). The size of piping to facilitate pumping requirements are calculated on a basis of several factors involving elevations, distances, flow rates together will electrical consumption efficiencies at the designated horsepower pump rating and turnover time-frame to achieve a complete cycling of the entire pool water volume. The Skimmer represents one of two sources of inlet water and should be balanced with the Main Drain in order to facilitate an equalibrium between the top and the bottom of the pools water volume. Due to the chemical additives required in maintaining the water chemistry, balancing the pH and OPR will involve the pool bottom suction (Main Drain) to proportionately represent an appropriate percentage of the suction inlet source of the pool water. Added chemicals are heavier that water and they will settle on the bottom. The Main Drain suction source will draw the pool’s bottom water and upon being combined with the Skimmer’s surface water a blending during filtration will provide a much greater uniformity in the even distribution of these water chemistry modifiers.
ANTI VORTEX DELUXE MAIN DRAIN (Pentair)
The Main Drain (s) are a device that causes bottom water to be drawn into an opening through a molded durable, non-corrosive ABS plastic body. This device is installed prior to gunite and accompanied by Anti-Vortex Lids Cover installed at finish plaster stage. This Main Drain devices are pre-fabricated by the manufacturer and as such during the installation process it is weaved between the swimming pool steel reinforcement skeleton and positioned in a fashion that allows the top of the body to correspond with the finish plaster elevations and a minimum of 3” cover of gunite over the steel reinforcement where they are located at the bottom of the pool. These devices are installed in a minimum of (2) two separated in distance ranging from 2’-4’ apart. The interior of the body has a recessed cavity that can receive deposits of debris from the pool bottom surface when being brushed and will assist the capturing of debris as the stirred debris concentrations mix with water flows through the cavity on it’s journey to the pump. Located at the bottom and side of this device are two pipe connections, the bottom connection is plumbed to an Collector Tube that together with a Hydrostatic Relief Valve providing hydrostatic pressure relief (See Hydrostatic Relief and Collector Tube). The side connections of the dual Main Drains are connected together by way of a larger pipe size and then “T” connected to a dedicated suction line (See Pipe Sizing) which runs to the pump. The size of piping to facilitate pumping requirements are calculated on a basis of several factors involving elevations, distances, flow rates together will electrical consumption efficiencies at the designated horsepower pump rating and turnover timeframe to achieve a complete cycling of the entire pool water volume.
MAIN DRAIN COLLECTOR TUBE (Pentair)
The Main Drain Collector Tube (s) are installed in the bottom connection of the Main Drains. These devices are of a cylinder configuration acting as a type of screen or sieve that will retain the (approx. 2 C.F.) ¾” crushed rock material that has been backfilled around it (before gunite) while allowing ground water to pass through the device (See Under Drain). The purpose of this device is to allow accumulated ground water to purge and pass through the screen / sieve when the Hydrostatic Relief Valve is open (See Hydrostatic Valve). This gravel deposits together with the geotextile filter fabric acts as a retainer regulating the flow rate of water migration into the pool. This process minimizes the risk of compaction disintegration through high flow ground water migration of the under-soil constituents below the gunite in cases whereas the pool is drained during unfavorable hydrostatic pressure conditions.
HYDROSTATIC RELIEF VALVES (Pentair)
The Hydrostatic Relief Valve (s) are installed in the bottom of the Main Drain cavity utilizing a male / female threaded connection with the Main Drain. The purpose of this device is to allow ground water trapped under the gunite pool shell to be relieved before causing the pool shell to float and rise or lift out of the ground. The Hydrostatic Relief Valve is designed with an “O” ring seat which retains it’s normally closed position by a spring load retraction mechanism that holds the bonnet firmly seated on the non-corrosive, non-conductive body lug. The spring loaded mechanism together with the load value of water depth keeps the valve closed when the pool is full of water. When the pool is drained and if there is an abundance of ground water present under the pool shell the valve will open allowing the ground water to purge into the pool relieving the hydrostatic pressure.
ISOLATION VALVES (Pentair MULTI-PORT & STRAIGHT THROUGH)
Isolation Valves are installed in an effort to provide concentrated affects on both the suction lines and the return lines (Chemical Balancing). In the process of plumbing the piping network it is important to maintain separation between the Skimmer (s) and the Main Drain (s). Additionally, it is important to provide separation and individual control between the grouping of the return lines, water features and other plumbing functions. After construction and during operational modification to the pool’s function it may involve desired adjustments that cater to seasonal influences of better serviceability and maintenance. In instances whereas manual vacuuming is required the Isolation Valves on the suctions side of the pump can be concentrated on the Skimmer providing maximum suction capability to the vacuum cleaning process. Another situation may involve brushing the pool down whereas concentration on the Main Drains would provide maximum suction capability at the bottom processing the maximum filtration flow rate through the Main Drain (s). Other benefits involve the distribution of chemicals that are heavier that water (Chlorine) and colder water that settles at the lower depths of the pool. This is especially true when involving gas or solar heated water distribution through floor return inlets (See Floor Return Inlets). Individualizing the control over surface movement in specific areas of the pool can also provided better directional functionality of the return line/ surface skimmer relationship assisting the drawing of floating surface debris into the throat of the Skimmer and capturing that material in the leaf basket before it has a chance to settle to the bottom.
CHECK VALVES (Pentair MULTI-PORT & STRAIGHT THROUGH)
Check Valves are installed in situations that involve checking or stopping a reverse flow of water. This usually is needed when pumping operations have subsided. Examples of this involve an elevated spa that is utilizing a common pump for pool and spa operations. If Check Valves are not utilized on both the return and the suction lines the elevation difference between the spa and the pool will cause the spa to drain back into the pool until reaching an equal surface level when and if a common piping route existed during manual or automatic malfunction. Another example would be a Hartford Loop in combination with a properly installed Swing Check Valve for an Air Blower. There are many different applications and types of Check Valves 90 Degree, Multi-Port, Straight Through, Swing and Spring type with spring weight variables that provide greater flexibility in the efforts of proper planning for the installation of pool equipment.
FLOOR RETURN INLETS (Pentair)
Floor Inlets are a device that are installed at the end of a Floor Return Line and outfitted with a diffuser that provides uniform, efficient, high velocity 360 Degree distribution of water. Floor Return Lines return water to the bottom of the pool rather than to the surface area. By directing returning water during the heating mode it can better mix the cooler bottom water that settles to the bottom of the pool with the returning warmer water. This can more effectively blend the variable temperatures and harmonize overall swimming enjoyment and usability. Additionally, this can provide a better blending of the chemicals necessary to maintain a balanced water chemistry.
UNDER DRAIN SYSTEM
In cases where an under drain is identified as a requirement by the engineer ( pre-inspection before erection of steel reinforcement placement is required if subterranean water is present) the under drain system will be installed by over excavating the bottom of the swimming pool to a depth of 8” greater than that that would facilitate the designed finish gunite depth. At the bottom of this sub-grade elevation a geotextile filter fabric (See Geotextile Specification) will be placed in adequate width to allow it to span the width of the pool’s entire deep end bottom and vertical side walls to a minimum of 18” from the center of the wall radius. The geotextile filter fabric will be folded back over itself in a fashion that will provide an encapsulation of the ¾” crushed gravel material separated from the native soil. The ¾” crushed gravel will be placed on top of the geotextile filter fabric in an approximately 8” depth and the geotextile filter fabric will be folded over the top and all sides of the ¾” crushed gravel. The lowest elevation of the swimming pool excavation will be at the Main Drain where the Dual or Multiple Main Drains will be outfitted with a Collector Tube and a Hydrostatic Relief Valve. If de-watering of the sub-soil strata is required after gunite the threaded Hydrostatic Relief Valve can be removed and a de-watering pump can be connected to the Collector Tube providing a purging mechanism of excessive ground water under the swimming pool.
SAND FILTRATION (Pentair TR-60, TR-100 & TR-140)
Sand filtration is a type of filtration that filters water by using a twenty mesh particle size silica sand as the filtering media. The filter is constructed of Filament Wound double walled tank with an internal hydraulically balanced Lateral Flow System (HBL). These filters offer the best environment for pump motor longevity and electrical efficiency because they don’t over filter at clean stage and have a tolerated restriction value when marginally dirty (See D.E. Filter & Cartridge Filter). These corrosion resistance extremely durable filters are equipment with a top mounted backwash valve that allows the simplest and easies way of cleaning your filter. Depending on size selection (See Filter Sizing) the sand volume will range between 400 Lbs. And 800 Lbs. and does not require disassembly for cleaning. When the filter becomes dirty the operating pressure will increase, indicating a reduction of flow and that it is time to backwash the sand media to rid it of the accumulated dust, dirt and debris that become captured in the sand. To accomplish backwashing you will manually turn-off all pumping then after a moment to allow for depressurization of the system you will re-position the backwash valve indicator from the filtering mode to the backwash mode. After accomplishing this you will manually turn the filtering pump on and watch through the Sight Glass adjacent to the Backwash Valve for one to three minutes or until the water becomes clear through the sight glass. At this point you will manually turn-off the pump taking a moment again for depressurization and re-position the Backwash Valve in the filtering mode. That will conclude the filter cleaning operations. After backwashing it is important that you check that the Autofill (See Autofil) is maintaining the proper water level. Depending on the pool size backwashing can deplete the pool of water that may effect the functionality of the Skimmer requiring you to add water before the next cycle of operation.
BACKWASH VALVE (Pentair TOP MOUNT)
All Sand Filters are equipped with a Backwash Valve that gets connected to the yard drainage system. This device allows backwashing operations to purge the captured microscopic dirt that has been filtered out of the water. The concentration of dirt would be that equal to storm water so that it will not effect the functionality of the drainage system. Sand filters are the only filter that can legally be flushed into a storm drainage system because the 15-20 micron level of filtration does not pose a health issue. An additional capability may become available next season for installations that incorporate a Pentair Itellitouch Control System and that is an “Auto-Backwash Valve” this device involves a sensor that measures pressure changes at the pump head as the filter become dirtier. The control system will reference the pre-settings registered in the control panel against the active pressure inside the piping system. When it reaches the pre-setting the pump will shut down and the control panel will display that the filter is dirty and backwashing is needed.
AUTOFILL-OVERFLOW (MP 1953-J)
The Autofill-Overflow device is a molded canister with an adjustable lid designed to be installed in concrete decking or a planter area. This device is connected to the pool via a 1” Schedule 40 PVC pipe providing free flow that runs horizontally from the pool into the canister about 8”-12” below the water line. When the canister is positioned in close proximity to the pool at set at the proper level (See Autofill Technical Information) this pipe allows the water level in the canister to seek the same level as the pool surface. The relationship thus is maintained and when the pool level drops it causes a float activated valve mechanism to open a valve that induces water to flow into the canister. This valve has a variable flow rate and is connected to a backflow protected pressure main water supply outfitted with an isolation valve. The lower the float dips the faster the water will flow and as the water surface approaches the pre-setting on the float mechanism the water flow rate subsides then stops. The range of actual flow rates may range from .0 to 5.0 GPM’s and will self adjust as the water raises to the established setting. A pool’s water level can change daily by as much as .50” of evaporation. Water features, Fountains and other water spraying devices can add to the effects of evaporation. The water loss from a pool @ .50” in depth equates to .31 GAL./SF in volume. An average pool size of 500 SF could related to 155 gallons of loss per day during the heat of a summer day. The Autofill mechanism will compensate for this loss over a period of time at a very slow flow rate. You could expect the Autofill to be operational in this example, .50 GPM’s flow rate divided by 155 gallons would equal to 310 minutes or 5.1 hours. Additionally, the Overflow line compensates for excessive water being introduced by natural precipitation or other influences. When the pool surface level raises above the Overflow’s outflow line leading from the Autofil canister to the yard drainage system excess water is purged. It should be noted that body mass acts as a displacement of water volume and so the more people that enter the pool the greater displacement will be. As a consequence every cubic foot of body mass will displace 7.48 gallons of water. In this example if ten children with a body mass of 1.5 CF entered the pool they would displace 112.2 gallons. This is a good reason to not only install an Autofill on the pool but also a separate one on the spa because the body mass displacement in a spa has a more dramatic affect on surface levels.
POOL CLEANER (Pentair Suction Side Cleaner)
Pool cleaners are a device that attaches to a dedicated return line (Some are suction propelled) and are most often operated by a separate booster pump. When designed correctly, a suction side cleaner can save electrical power by eliminating a Cleaner Booster Pump requirement.
Cleaners are designed to travel along the bottom and sides of the pool collecting dirt, leaves, debris and some have a debris bag or compartment that needs to be maintained combined with trailing line jets and whip hose that power out surface dirt. They typically run within the time window period that has been designated “Filter Mode Operation” so that the disturbed water suspended surface dirt can be filtered out. While running the filter pump and the cleaner pump the voltage loss through the main electrical conductor is increased reflecting not only more power but more power with lost kilowatt usage. This lost power is after the meter so you are being charged for that whether you received any value or not. The Pool Cleaner’s Booster Pump operates together with the filter pump on a dedicated return line after the pool filter via a separate return line. This cleaner swiftly glides across the walls and floor of your pool while silently vacuuming all the debris in its path. It’s venturi-action and simple water powered propulsion vacuums as it travels throughout the pool.
If a Booster pump style cleaner is selected then the electrical calculations need to consider the full intentions of operational functionality for all electrical loads. Wire sizing from the main electrical service to the swimming pool equipment pad should take into account achieving a not to exceed 3% one way voltage loss under operation conditions.