TAKING CONTROL OF THE PRESSURE-REGULATING VALVE
EDITOR’S OPINION
The One Meridian Plaza fire in Philadelphia, Pennsylvania, raised some important issues about high-rise firefighting, not the least being the fire service’s understanding of valves on standpipe connections that automatically control flow, and therefore pressure, at the hose outlet. In the wake of that tragedy, the pressure-regulating type of hose valve (PRV) has drawn considerable attention. Many in the fire service are asking questions and seeking answers.
Frankly, that’s not too soon in coming. PRVs have been around for about 15 years and are components of literally thousands of standpipe systems in this country. A fire service suddenly on the “alert” is a statement in itself; nevertheless, we are communicating on the PRV issue, and no time is better than the present.
hike many features of modern high-rise buildings, the existence of PRVs is attributable directly to cost. Single standpipe risers are less expensive than zoned systems and therefore are preferred by many building designers. The building’s automatic fire pump(s) produces as much pressure at the base of the riser as is needed to produce sufficient pressure at the top, so it’s not uncommon to have hundreds of pounds at lower floors. To regulate the unwanted high pressures (in excess of 175 psi) at lower-floor connections—under both flow and no-flow conditions—PRVs are installed.
The main advantage of the PRV is that it minimizes the risk of injury from a firefighter receiving a threeor tour-hundredpound jolt of pressure at the nozzle. It also eliminates the need to position a firefighter at the standpipe connection to manually regulate the flow (a plus in these days of three-member engine companies) and lessens the chances of a hoseline bursting or a nozzle malfunctioning under extreme water-pressure conditions.
by the same token, an improperly calibrated PRV will regulate the pressure to the extent that it turns an attack line into a garden hose. It’s not difficult to understand, particularly in light of the Meridian Plaza fire, why the PRV is perceived as a villain that hits the fire department where it hurts most —in its ability to control its water supply The virtually unremovable, practically non-fieldadjustable PRV takes pressure control at the fire floor out of fire department hands. There’s no redundancy in a PRV setup should the valves at the fire floor and those below it be Incorrectly set to produce less-than-desircd pressure at the nozzle tip. save for your “backup standpipe” (running 1.1)11 up the stairwells), by which time your opportunity tor an effective aggressive attack on the fire is diminished if not eliminated. That’s not a comforting thought.
What can be done? The fire department must take control of the PRV—as it must take control of the entire standpipe system and all its other electrical and mechanical firefighting systems— before the fire starts:
- Become thoroughly educated in all types of hose valves, including pressure-regulating and pressure-reducing valves, and how they operate. This should be required knowledge for all firefighters.
- Identify (preplan ) all PRVs in your jurisdiction. Know the operating pressures of each system.
- Conduct an immediate needs analysis of what you require tor
- a complete, rigorous inspection and testing program of all standpipe systems in your jurisdiction. Then develop a plan.
- “Sell” the plan. Building the resources for any comprehensive plan is difficult, given the state of today’s manning levels and budgets. But what’s the alternative here? Make certain that all the players understand the consequences when a fire department is unable to get water quickly on the fire. Show them pictures of the aftermath of One Meridian Plaza. An extensive inspection and testing program cannot and should not be shouldered by the fire department alone. Perhaps contracting a professional engineering firm to perform the testing, paid for by the building owner, is the way to go.
- Rewrite your local code. Make regular inspection and testing of each valve a law.
- Enforce the code. Penalties for noncompliance should be severe, and that’s only fair: Facing down a high-rise fire without water is a severe situation, to say the least.
- Communicate. Bridge the gap between the fire service and the engineering community. Talk to the manufacturers of standpipe system components; explain your concerns. Work for improvement, not antagonism. Maybe there’s a way to design a visible means of verifying a valve’s actual pressure setting (beyond a mark on a label). Maybe there are ways to make field adjustment of PRVs practical. Perhaps a removable PRV will allow for less-expensive, on-site flow tests of individual valve assemblies. Encourage field tests. The Boston Fire Department, for example, has entered a joint effort with Schirmer Engineering and The Prudential to conduct tests on the various PRVs and their performances.
- Participate in updating national codes and standards. For instance, as they exist now, NFPA 14 and 14A contain just a few lines of text on PRVs. NFPA 14 currently is being rewritten and will include acceptance testing for new systems, including testing of PRVs. A new standard, NFPA 25, Inspection, Testing, and Maintenance of Water-Based Fire Protection Systems, will be proposed at the association’s fall meeting in Montreal. Get involved.
- Revise your SOPs to include operations with PRVs. Detail contingency plans in case PRVs fail during an operation, and drill on them.
- If careful analysis of all the variables dictates—that is, if it’s right for your department and your community—ban PRVs from future construction in your jurisdiction. This, however, does not eliminate continued testing and operational preparedness for all existing standpipe systems with PRVs.
The variables associated with PRV performance are many: from factory calibration specifications to proper installation to simple human error or carelessness. The way to deal with this and any technology is to plan ahead, test it, and train in its use. It’s the only way to simplify fireground operations and eliminate unpleasant surprises.