How does a deluge valve differ from a standard alarm valve in a wet system?What are differences from a standard wet pipe system regard alarm trim and NPFA codesAlso if an existing system, over 2000sft, (pipe sched method) has no siamese connection, and I am adding addtional heads via the same pipe schedule method - Am i required to upgrade the riser/alarm trim to include a fire department connection? - (re:NFP13, 2002)
An alarm valve is a check valve with a method of getting pressure or slight flow from an auxiliary port. The alarm valve opens when pressure on the system side is low enough for supply pressure to open it. then some water goes out the alarm port to a pressure switch or water motor gong. A deluge valve is a normally closed valve, opened by a stimulus from other than pressure on the system side. Typically the stimulus comes from a heat detector for electrically operated systems, or loss of pressure in a pilot line. The pilot line is provided with air or water pressure, and has fusible plugs or sprinklers for detection, mounted in appropriate locations. If the pilot line loses pressure, the deluge valve opens automatically. Manual operating features are always included. Rarely, one finds deluge systems that are manually operated only. The alarm trim can be identical for alarm and deluge valves. If you are charged with designing a system in accordance with NFPA 13, a fire department (siamese) connection is required. Exceptions are: 1. Fire suppression forces (if any) do not have the facilities for providing water to the fire department connection. 2. The authority having jurisdiction waives the requirement. Of course you would want the owner to agree also.
Open sprinklers or spray nozzles are attached to piping and to the valves. The valve is connected through control valves to a water supply system. The deluge valve consists of a housing, a swinging clapper like an ordinary check valve and a retractable keeper to hold the clapper tight to the valve seat. Electrical pneumatic or hydraulic mechanisms can retract the keeper, causing the valve to open. Other attachments provide for alarm sensors, gages and the like. See one at the link below
Normally sprinkler can classify as either wet type or dry type. In which under the Wet type system you will have pre-action, deluge and Dry pipe. Of course in anycase wet pipe is the best due to its economic reasons. Indeed, ppl spec for dry type because of afraid fault alarm, accident damage, low temperature (maybe less than 10 degree C) of production area and so on and forth. Generally, deluge valve can be manual or automatic. It doesn't have sprinkler bulb head. Upon detection of fire, responsible person shall operate the alarm valve manually. If automatic features is installed, Heat and Smoke detector will detect the fire and trigger the alarm valve to open and the water flow in. You need to calculate the Design Density to size up your tank properly. In your case of just only an extension of building and not construction from empty land, you may need to study on the existing fire fighting system to which standard it has been designed from. From there, you can extend by maybe adding another alarm valve, and so on and forth. Mechanical Consultant will able to assist you in this. You may write to me and tell me more about the form, feed and funtion of the building so that i can provide more ideas on this....
This Site Might Help You. RE: What is a Deluge Valve? (Fire Suppression)? How does a deluge valve differ from a standard alarm valve in a wet system? What are differences from a standard wet pipe system regard alarm trim and NPFA codes Also if an existing system, over 2000sft, (pipe sched method) has no siamese connection, and I am adding addtional heads via the...
