Water resource is the fundamental agent for fighting fires; furthermore, water is also cheap and efficient as compared to other firefighting agents. Water is undoubtedly used, in one form or another, by every fire service to fight fires.
This could not be achieved without Pressure Reducing Valves (PRVs), which means PRVs play a significant role in any firefighting system’s battle against fires.
It’s not uncommon for normal inner pipe pressure to exceed the safe operating pressure at which portable firefighting equipment runs, and this might cause potential risks. PRV can help to reduce, or optimize, the pressure of water from a fire main via a fire hose for handheld nozzles to deliver desired firefighting water, thus eliminating the risk of overpressure.
PRV’s downstream pressure can be set optimally and maintained even if the supply pressure changes or system load varies.
PRV valves come in a wide variety of inlet styles (threaded or flanged) with multiple outlet adaptors to match all equipment in use worldwide.
A new requirement for Low Pressure Friction Loss Testing to PRVs was first introduced by FM approvals in October 2017 to the PRV Approval Standard (FM1362) in accordance with section 4.11 of FM 1521/1522. This new standard stipulates that the measured friction loss shall be less than 10 psi.
In addition, the minimum water flow rate shall be through the valve of no less than 8.5L/s (510 lpm) and an outlet pressure of no less than 4 bar given that the inlet pressure is 4.7 bar.
For the stated flowrates above 125gpm (125l/min) to earn FM Approval, the only permitted option is to have a 2 1/2” valve that meets aforementioned requirements. For valves used at high flow rates, 1 1/2” valves are not to be certified.
With a working pressure as high as 20 bar when used on fire mains, the MAFCO’s outlet pressure can be set at customer’s request to meet the requirements in the range of 3 to 8 bars.
Used mainly in wet rising mains, among others, in buildings, the MAFCO PRV is versatile enough to be used with fresh, brackish, or sea water. Furthermore, this re-designed PRV is suitable for use in lower temperature regions due to its ability to deal with problems related to water freezing.
Mafco applied for PRV Approval in 2016, and the next year FM announced that all PRV products need to meet a new requirement of friction loss test (less than 10 psi) and requested re-testing of the FM certified PRV manufacturers.
Mafco went through 2 years of hard work and earned the new FM Approval in 2019, becoming one of four FM certified PRV manufacturers in the world.
Among the other three manufacturers, the British one as linked on our blog only has its 2.5” PRV approved while the rest passed the friction loss test by reducing the valve inlet diameter to 1.5” (the smaller the inlet, the less the friction loss). Mafco, however, is the only PRV manufacturer producing FM-approved PRV with 2.5” bib nose.
Bib nose is the most common PRV style whose friction loss is higher than that of oblique and other styles due to its shape. To provide the best PRV for our customers, we at Mafco overcame all the challenges and have our bib nose PRV approved by FM while our competitor only holds the oblique approval.
