High-Rise Operations Manual PDF

SECTION TOPICS NFPA Standards Giacomini Pressure Reducing Valve PRD vs. PRV: What is the Difference? Urfa Pressure Reducing Valve Pressure Restricting Devices Zurn Pressure Reducing Valve Factory Pre-Set Non-Adjustable Pressure Reducing Valve SECTION OBJECTIVES Be able to define NFPA 101 Be...

SECTION TOPICS NFPA Standards Giacomini Pressure Reducing Valve PRD vs. PRV: What is the Difference? Urfa Pressure Reducing Valve Pressure Restricting Devices Zurn Pressure Reducing Valve Factory Pre-Set Non-Adjustable Pressure Reducing Valve SECTION OBJECTIVES Be able to define NFPA 101 Be able to define NFPA 14 Understand and explain the differences between PRDs and PRVs Understand what tools are needed to adjust various types of PRVs Understand how to identify and remove various types of PRDs Be able to identify and adjust a Giacomini PRV Understand the importance of identifying factory set non-adjustable PRVs early in the high-rise operation Be able to identify and adjust an Urfa PRV Understand what tactics to use when a factory pre-set non-adjustable PRV does not provide adequate pressure Be able to identify and adjust a Zurn PRV Second Edition 01/11/22 33 OVERVIEW To operate in the high-rise environment, firefighters need to have some background about how high rises are constructed. Just like anything else in the fire service, high-rise buildings are constructed to meet standards to ensure their safety for the occupants and first responders. NFPA 101 Defines a high-rise as a building greater than 75 feet in height, where the building height is measured from the lowest level of fire department vehicle access to the highest occupied floor NFPA 14 For buildings constructed pre-1993: Requires that these buildings standpipe systems provide 65 PSI of residual pressure at the most remote outlet from the fire pump, while flowing 500 GPM Buildings constructed post-1993: Requires that these buildings standpipe systems provide 100 PSI of residual pressure at the most remote outlet from the fire pump, while flowing 500 GPM Requires that excessive pressures in a standpipe system are to be reduced at the outlet to a manageable level o If the pressure at the outlet is less than 100 PSI, then no pressure reduction is required o Pressures between 100 PSI and 175 PSI require pressure restricting devices (PRD) Note: Pressure restricting devices only reduce pressure when flowing o Pressures over 175 PSI require pressure reducing valves Note: Pressure reducing valves reduce pressure in both static and flowing conditions CFD HIGH RISE DEFINITION Any building that is 75 feet or greater in height or is out of reach of a CFD aerial or platform is considered a high-rise building. This is how CFD members have interpreted the definition of NFPA 101 over the years to apply to our division 5199 E. Broad Street Mother Angeline McCrory Manor is a four-story high life hazard nursing home facility with no access for aerials/platforms on the south side and limited scrub area on the north side Second Edition 01/11/22 34 OVERVIEW The following chart provides an overview of common differences and characteristics of PRDs and PRVs. Pressure Restricting Devices (PRDs) Pressure Reducing Valves (PRVs) Used in standpipes with internal pressures from Used in standpipes with internal pressures 100-175 psi greater than 175 psi PRDs are external components that can be removed. PRDs are usually a device added onto the outside of the valve, or an insert placed into the mouth of the valve Pressure reducing valves have an internal mechanism built into the valve body that regulates outlet pressure. These internal components cannot be removed Reduces pressure in flowing conditions only Reduces pressure in static and flowing conditions Can usually be easily removed or defeated Are either factory preset non-adjustable valves, or are field adjustable Does not serve as a one-way check valve Most act as a one-way check valve that does not allow water to be back-fed into the standpipe A threaded stem inside the valve indicates the A smooth stem inside the valve indicates the valve is not a pressure reducing valve valve is a pressure reducing valve Some common PRDs include adjustable pins, Common PRVs include the factory pre-set nonremovable clips, orifice plates, and mechanical adjustable valves, Giacomini valves, Urfa valves, restricting devices and Zurn valves Does not provide a steady discharge pressure Can compensate for variations in inlet pressures because they cannot compensate for inlet (to a certain extent) by balancing water pressure pressure changes in an internal chamber, typically against a spring Click here to view Brass Tacks and Hard Facts video about types of standpipe outlet valves Click here to view Vector Solutions video on PRVs and PRDs In buildings that have PRVs on the standpipes, it is especially important for the pump operator of the FDC engine to know what pressure the fire pump is providing to the building. If the fire pump fails and the FDC engine must take over supplying the building with water, the pump operator should supply the building with the pressure that would be required at the top floor (Supplying the same pressure that the building fire pump was discharging should be adequate for this). If the pump operator supplies a lower pressure than the fire pump did, the PRVs will not allow adequate pressure past them to provide the appropriate pressure needed by the fire attack teams. If the fire pump discharge pressure is not known, many FDC engine pump operators would likely try to figure up what pressure would be needed at the fire floor. Even if the fire floor is only part of the way up the building, (for instance, floor 20 in a 40-story building), the FDC engine pump operator should actually determine what pressure would be needed at the top floor and should then supply that pressure to the building. Doing so ensures that the appropriate amount of pressure will make it past the PRVs on the fire floor. Second Edition 01/11/22 35 OVERVIEW Simple external device placed on or into a standpipe outlet valve Many different designs including orifice plates, mechanical, or limiting devices Reduce pressures in flowing conditions only Used in standpipes with internal pressures from 100 175 psi Typically not field adjustable, but can usually be easily broken off or removed ADJUSTABLE PIN DESIGN Simple external device that is easily removed or broken Limits the valve from being opened completely Only reduces pressure during flowing conditions Remove using an Allen wrench or break the flange using a Halligan Once removed, the valve can be fully opened Use Allen wrench to loosen two set screws, then remove the device REMOVABLE CLIP DESIGN Simple external device Easily removed Limits the valve from being opened completely Reduces pressure during flowing conditions Remove by pulling the clip out of the valve Once removed, valve can be opened fully ORIFICE PLATE Metal disk with a restricted opening, similar to a large metal washer Located inside the threaded male outlet of the standpipe valve Can cause damage to the inner lining of hoses Does not provide a steady discharge pressure because it cannot compensate for inlet pressure changes Pry it out with a small screwdriver, or pull it out with a pair of channel locks Second Edition 01/11/22 36 MECHANICAL PRESSURE RESTRICTING DEVICE One-piece mechanical device designed to reduce outlet pressure Similar in size to a double female adapter Mostly found in older buildings Has hose threads on both ends Device threads onto the male outlet of the standpipe valve Only reduces pressure during flowing conditions Inside the device are overlapping holes that restrict the water flow through the device Device can be manually adjusted by turning the external knob on the side of the device to set the overlapping holes in any position from fully closed to fully open (NOT RECOMMENDED) Do not attempt to adjust the device. Simply remove it by unscrewing it from the standpipe outlet threads External knob used to adjust the device View inside the waterway of the device showing the overlapping holes mechanical pressure restricting device Unscrew the device from the standpipe outlet threads Second Edition 01/11/22 37 IDENTIFICATION AND FEATURES Pressure-reducing valve that has its pressure reducing characteristics pre-set at the factory during the manufacturing process NON-ADJUSTABLE VALVE, the pressure cannot be changed on the fireground Specifically designed to be installed on a certain floor of the building If valve is installed on the wrong floor, it will result in inadequate pressure output Early identification of these valves is vital to allow firefighters time to consider other water supply options if there is inadequate pressure at the valve Valve is identified by a large ring at the top of the valve body; some may have a label on the valve indicating it is a pressure-reducing valve Remove the cap from the outlet and look inside the valve. A smooth stem typically indicates a pressure-reducing valve; a threaded stem typically indicates a standard hose valve Note the large ring at the top of the valve body. This valve also has a label indicating it is a pressure reducing valve Photo on the left shows a valve with a threaded stem (standard control valve) and a valve with a smooth stem (pressure reducing valve) Note the small 3/8 inch waterway opening on this Powhatan pre-set PRV. This still provides adequate volume, but at a low pressure Factory pre-set valves leave much room for human error because the valve must be designed properly, assembled properly, installed properly, installed on the right floor, flow tested, and properly maintained to ensure proper operation. Those factors, combined with the fact that these valves are non-adjustable, make the factory pre-set valve the least desirable standpipe valve for firefighters to deal with. Second Edition 01/11/22 38 IDENTIFICATION AND FEATURES Large valve with exposed adjustment barrel Valve body made of casted bronze Field adjustable Adjustment instructions printed on valve body 4 holes in adjustment barrel for adjustment rod usage 2 ½ inch male outlet connection FIELD ADJUSTMENT Purpose Allows firefighters to overcome valve installation or maintenance problems that cause inadequate pressure at the valve outlet Tools Required metal adjustment rod Adjustment Procedure Insert adjustment rod into exposed hole in adjustment barrel Rotate adjustment rod clockwise to increase standpipe outlet pressure, or counterclockwise to decrease outlet pressure Rotation of adjustment barrel requires 75 pounds of force Numbers etched into the adjustment barrel refer to approximate PSI at zero flow. They do not correspond to flow under residual flow conditions Firefighters can use these numbers to approximate what the outlet pressure will be, but they will not be completely accurate since they correspond to zero flow Hole in adjustment barrel for adjustment rod use Labels on the valve provide instructions on how to adjust the valve pressure Second Edition 01/11/22 39 IDENTIFICATION AND FEATURES Similar in appearance to Giacomini valve Large field adjustable valve with adjustment barrel covered by Lexan anti-tamper shield Adjustment instructions printed on anti-tamper shield Holes in adjustment barrel for adjustment rod use 2 ½ inch male outlet connection FIELD ADJUSTMENT Purpose Allows firefighters to overcome valve installation or maintenance problems that cause inadequate pressure at the valve outlet Tools Required T-handle pin and hex security wrench adjustment rod Straight screwdriver Weak point of Lexan shield Adjustment Procedure Use pin and hex wrench to remove set screw, or break Lexan shield at its weak point with straight screwdriver if no pin and hex wrench is available Uncover the adjustment holes by either sliding the Lexan shield up out of the way, or rotating the shield until the adjustment hole is accessible through the slot Insert adjustment rod into exposed hole in adjustment barrel There are arrows on the Lexan shield showing which direction to turn to increase or decrease pressure Set screw located in shield slot Rotation of adjustment barrel requires approximately 15 pounds of force Lexan shield lifted to expose adjustment hole Turn Lexan shield until adjustment hole is accessible through the slot in the shield. Insert adjustment rod. Rotate adjustment rod clockwise to increase pressure or counterclockwise to decrease pressure. Click here to view Brass Tacks and Hard Facts video on Urfa valve use and adjustment Second Edition 01/11/22 40 IDENTIFICATION AND FEATURES Large valve with a long stem Hand wheel for opening and closing valve Removable bonnet 2 ½ inch outlet connection Field adjustable FIELD ADJUSTMENT Purpose Allows firefighters to overcome valve installation or maintenance problems that cause inadequate pressure at the valve outlet Tools Required pipe wrench Ratchet with 1 deep well socket Adjustment Procedure Open valve by turning hand wheel counter-clockwise Loosen the upper coupling nut with the pipe wrench Remove the hand wheel assembly (bonnet) Insert the 1 deep well socket onto the adjustment nut Tighten the adjustment nut to increase the outlet pressure of the valve, or loosen the adjustment nut to decrease the outlet pressure of the valve Utilize 18 inch pipe wrench to loosen upper coupling nut Remove bonnet Utilize ratchet and 1 1/16 inch socket on adjustment nut. Tighten the adjustment nut to increase pressure, or loosen the nut to decrease pressure Firefighters and Incident Commanders with a limited understanding of pressure reducing valves tend to be the most uncomfortable with the Zurn pressure reducing valve due to the need to remove the bonnet for field adjustment. Proper preplanning and understanding of the valve allow for proper adjustment of the valve when necessary. Click here to view Youtube video on adjusting the Zurn PRV Second Edition 01/11/22 41