This way, we can control the valve’s closing and/or opening speed as required, and soften the surge effect to a bearable level.įor a variety of reasons, the jockey pump or maintenance pressure can often be set substantially lower than that of the system's operation pressure, so when a pump starts in a pressurized fire protection system, it has to raise the pressure held in the system by the jockey pump up to the system operating pressure. Despite this, there is occasionally a need for valve reaction control when the level of surge pressure is intolerable and piping and instruments must be protected.Ĭertain valves can be equipped with a reaction speed device to control the rate of opening and/or closing to avoid damaging surge. Most fire protection systems take into consideration the aggressive nature of fire protection water flow, designed to get the extinguishing media to the application devices in the shortest time possible. Water hammer can be caused by overly fast reaction of fire protection valves. When needed this valve can double/triple up to be used as a pressure control valve and a check valve whilst simultaneously preventing surge or water hammer damage at pump start up.ģ. When the pump starts the initial surge will be prevented by the closed valve that will continue to open, releasing water into the system in a controlled manner preventing any surge or water hammer.Ī good example of such a valve is the UL listed BERMAD 42T-20. When the fire pump is dormant this valve will be held closed using the system jockey pump pressure. When the pump start-up momentarily creates an intolerable surge level, a Fire Pump Control valve suitable for most pump configurations presents an efficient all-round solution. Anti-Surge Fire Pump Control and Check Valve As soon as pump pressure below the set maximum arrives at the valve inlet, the valve will close and continue to work as a relief valve.Ģ. The following five solutions present some favored approaches to addressing water surge or hammer problems.Īn effective way to prevent surge or water hammer deriving from the start-up of Vertical Shaft Turbine Pumps is to use a normally open pre-emptive adjustable relief valve such as the BERMAD model FP-730-48-BL to prevent the pump start surge wave at the source.Īs it is a normally open valve, it will efficiently relieve any air and surge potential on pump start-up. There are a number of different methods that can be employed to lessen or prevent pressure surges.
#The surge 2 best hammer cracked#
The pictures below show two examples of catastrophic damage to piping and accessories caused by water surge/water hammer in fire protection systems.Ī valve casing cracked by surge pressure, Piping breached by water hammer.ĥ Ways to Prevent Water Pressure Surge in Fire Protection Systems Pressure waves from water hammer or pressure surge can easily exceed 50 barg (740 psi), thus creating a very real threat of damage to piping and instrumentation. Most fire protection systems are designed to operate at a maximum working pressure of 12 barg (175 psi). This momentum change can create a significant and potentially damaging pressure rise. Pressure surges in fire water systems can be caused by a number of different factors, such as a valve closing or opening too quickly or a pump starting or shutting down suddenly. Water surge or water hammer is a pressure w ave in a piping system caused when a fluid i n motion is forced to stop or change velocity or direction suddenly.
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