These are definitions of some of the terms used on this website as well as in the swimming pool cover industry. If you have any questions please Contact Us.

• Air blower - a device used to blow a continuous stream of air under a pool cover fabric during opening and closing. This is sometimes required on large covers with substantial amounts of deckdrag.
• Air channel - a system for introducing a volume of air into a hallow ducting built into a pool wall or into the deck, activated by the air blower.
• Barrier - a means to limit, delay or restrict access to a pool or spa. (Refer to ANSI/NSPI-8 Model Barrier Code for Residential Swimming Pools, Spas and Hot Tubs)
• BTU - British Thermal Unit
• Calcification - the formation of calcium carbonate on the walls of pools and adjoining structures, due to the precipitation of calcium carbonate.
• Cantilevered - the overhanging of coping around the perimeter of the pool or spa.
• Conduction - the spontaneous transfer of thermal energy through matter, from a region of higher temperature to a region of lower temperature.
• Coping - the cap on the pool wall that provides the finished edge around a pool or spa. Generally made from precast masonry, poured concrete, or brick. Can also be formed from metal, plastic or natural stone.
• Cover - something that covers, protects or shelters a pool or spa.
• Cover fabric - the portion of an automatic pool cover system that actually covers the swimming pool surface. These vinyl fabric come in varying weights from 14 to 20 oz. per sq. yard. UV and chlorine inhibitors are placed in the fabric during the manufacturing process. 
• Deck - the area immediately adjacent to or attached to a pool or spa that is specifically constructed or installed for sitting, standing or walking.
• Drag (surface tension) - the effect of a pool cover pulling across the surface of the deck. This action causes a measurable amount of surface tension. Factors such as deck texture and moisture can make the amount of drag more or less.
• Equipment area/pad - an area used to house recirculation and disinfecting equipment and related appliances.
• Evaporation - the conversion of liquid molecules into vapor.
• Float Valve - a valve controlled by the level of a liquid.
• Freeze-Thaw Cycle - seasonal weather and temperature changes that cause stress to a surface.
• GFCI - (Ground Fault Circuit Interrupter) a mechanism that cuts the current to a electrical device the moment a change in voltage occurs.
• Grounding - connecting or providing a conducting path to earth or a conducting body that serves in place of earth.
• Guide -  a piece of material at the starting edge of the track which allows the cover fabric's beaded side edge to feed smoothly into the track without coming out.
• Heat Loss - the natural drop in water temperature as heat is transferred to the air.
• Leading Edge - the front rigid supporting edge of an automatic swimming pool safety cover. Can be supported at each end by sliders or wheels or a combination of both.
• Make-Up Water - fresh water used to fill or refill a pool or spa.
• PSI - abbreviation for pounds per square inch.
• Recessed housing - the vault in the ground at the end of a swimming pool that contains the drive mechanism for an automatic safety cover. Must have a means to drain accumulated water. Can be shot with pool gunite or formed out of lumber. Many cover manufacturers as well as pool manufacturers supply prefab housing kits.
• Remote switch - any switching device used to activate an apparatus from a distance (remote location). Not to be confused with a RF (radio frequency) control i.e.,garage door opener, TV remote.
• Ropes - the ropes used to pull the cover fabric across the swimming pool are constructed of a cotton/polyester braid. They are densely constructed and have a very low stretch characteristic. 
• Safety cover - a barrier (intended to be completely removed from pool or spa surface before the entry of bathers) for swimming pools and spas, that will when properly labeled, used and maintained in accordance with the manufactures published instructions, reduce the drowning risk of children under the age of 5 years. Specifically, safety covers are meant to inhibit small children access to the water and to provide for a means by which to remove any substantially hazardous level of collected surface water.
• Skew - a slanting direction or position of the leading edge of a swimming pool cover at the end of travel.
• Slider - a rigid piece of plastic that is attached to the leading edge of a pool cover and allows for longitudal movement in the tracks.
• Torque Limiter - a device which limits the amount of torque applied to the drive mechanism of a automatic cover. When adjusted properly it will allow the drive motor to slip when the end of travel is reached.
• Track - the aluminum extrusions that the cover fabric and ropes move through to cover and uncover a swimming pool. Can be below deck or above deck. Sometimes referred to as guides or rails.
• Webbing - the side beaded edges of a cover fabric, can be sewn on or heat welded.