The standard ball float valves used in the GFTS15, GFTS22, GFTS15A, GFTS22A, GFTS15AH, GFTS22AH, GFTS15HSA, GFTS15AHCSA, GFTS22HCSA and GFTS22AHCSA are suitable for 2-10 bar pressure. If the site water pressure is higher than 10 bar, a high pressure ball float valve must be installed.
Bar vs. PSI
A bar is a metric unit of pressure exactly equal to 100,000 Pa (Pascal). Another way to look at it is that a bar is roughly the equivalent of atmospheric pressure on the Earth at sea level. Standard sea level pressure is defined as 1 bar.
It can be very useful to convert pressure measured in bar to pounds per square inch (psi). The conversion factor for such an activity is 1 bar = 14.5037738 pounds per square inch. When measuring pressure for ball float valves in in piping, it is common to use the pounds per square inch measurement. Thus, the ball float valves used in the GFTS family of gravity-fed tank safety showers are suitable for a psi range of roughly, 29.0 to 145.0 psi.
Connecting a water line to a gravity-fed cubicle safety shower/eyewash is a matter of choice and convenience. The S&E GFTS gravity-fed safety showers sold by Alpine Technical Services are stand-alone, self-contained products that will accommodate a direct water line for ease and convenience in refilling the water reservoir, however each unit can also stand alone, without any water connection. If the safety showers are used in this manner, the water reservoirs must be filled by the use of a potable water truck/trailer. The water must be potable in order to comply with the current ANSI Z358.1 (2014) standard and with OSHA regulations.
Gravity-fed Cubicle Safety Shower
If a gravity-fed cubicle safety shower is connected to a pressured water line, when the position of the ball float valves drops to a pre-set level, the dual valves will open, allowing the pressurized water to enter the tank. The rising level of the water will raise the ball floats until the float arm reaches the pre-set level that shuts the float valves.
The level of potable water in the gravity-fed safety shower is easily determined by a glance at the exterior water level indicator provided on the front of all S&E gravity-fed cubicle safety shower/eyewash units.
One of the best uses of these innovative safety shower products is for areas where water pressure will not provide the required 20 gpm (shower) and 0.4 gpm (eyewash) as required by OSHA and as outlined in ANSI Z358.1 (2014).