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Diesel Engine Cooling Loops

Make sure you are in compliance with FM Global's requirements for cooling loops on diesel engines. FM Global  Approval Standard 1333  was updated in 30 Nov 2013, but compliance was not required until 1 April 2015. Clarke Fire has an excellent write-up on their web page that you can find here . But, we wanted to summarize the key requirements. FM Approval - Cooling loops are now required to be approved and therefore they will have the FM logo on a nameplate. Low Raw Water Flow Alarm - This switch is set to activate at 75% of the required flow rate. High Raw Water Temperature Alarm - This switch is set at 105F (40C).

Installation of Diesel Fuel Tanks for Fire Pumps (OLD)

This article is based upon 2009 IFC codes and is obsolete. See newer version here: After you have determined the size of fuel tank you need for a diesel fire pump, what are the general requirements for installation?  Assuming that you are under under the International Building/Fire Codes, you would go through the following chain of code references: IFC (2009 edition) 3401.2 Nonapplicability. This chapter shall not apply to liquids as otherwise provided in other laws or regulations or chapters of this code, including: ... (3) Storage and use of fuel oil in tanks and containers connected to oil-burning equipment. Such storage and use shall be in accordance with Section 603 . For abandonment of fuel oil tanks, this chapter applies. IFC (2009 edition) 603.1 Installation. The installation of nonportable fuel gas appliances and systems shall comply the International Fuel Gas Code. The installation of all oth

Fire Pump Sensor Recall

Gem Sensor 3100 Recall Notice On April 24, 2012 the Consumer Product Safety Commission (CPSC) issued a press release, CPSC #12‐156 , for the voluntary recall of Gems 3100 Pressure Detectors/Transducers because the transducer can fail to accurately detect water pressure in a fire suppression sprinkler system. This could cause the sprinkler system to fail to activate and pump water to the sprinklers in the event of a fire. The failure associated with the Transducer is not a sudden loss of function but rather a slow degradation of performance over many hours of continuous use with constant water pressure. The use of the transducer in non‐water and/or fluctuating pressure applications has not shown the same potential problem. The sensors are basically failing in a "high" pressure rating (e.g. will read 100 PSI higher than actual pressure).  So it is easy to spot, but does require good on-going maintenance.  One should install a calibrated gauge and compare the pressures.

Pressure Relief Valves with Diesel Engines

Circulation Relief Valve When is a pressure relief valve (PRV) required on a fire pump system?  For a standard 175 PSI rated system, the simple answer is check and make sure that your expected churn pressure plus maximum static suction pressure  will not exceed 144.6 PSI  (or 206.6 PSI for a 250 PSI rated system).  The sizing of the relief valve comes from NFPA 20 (2010 edition) table 5.25(a) which is summarized in our fire pump sizing app .  For those of you that like to know the details read on. First let's clarify that we are taking about a main pressure relief valve and not a circulation relief valve.  A circulation relief valve is generally 3/4-inch in size if less than 3,000 gpm and intended to provide a little fresh water into the pump casing for cooling purposes . Pressure Relief Valve When we say pressure relief valve in "fire pump" terminology, we are referencing a PRV that is only provided on diesel fire pumps to accommodate possible engine over

Reliable Electrical Power for Fire Pumps and Backup Power

* Note that the 2016 edition of NFPA 20 changed the 4-hour to 10-hours of continuous outage * When do you need backup power for an electric fire pump?  The simple answer is when the power is "reliable".  Of course the word reliable means a lot of different things to different people.  Interestingly, NFPA 20 did not define reliable power until the 2007.  Thankfully the committee did agree on the following language: NFPA 20-2010 A.9.3.2 A reliable power source possesses the following characteristics: (1) The source power plant has not experienced any shutdowns longer than 4 continuous hours in the year prior to plan submittal . NFPA 25, Standard for the Inspection, Testing, and Maintenance of Water-Based Fire Protection Systems, requires special undertakings (i.e., fire watches) when a water-based fire protection system is taken out of service for longer than 4 hours. If the normal source power plant has been intentionally shut down for longer than 4 hours in the past, it i

Pump Rotation

For a horizontal split-case fire pump the rotation is defined by looking at the drive side of the pump unit. This means that if you were sitting on the motor and looking at the pump, a right-hand (clockwise) rotation has suction on the right and a left-hand (counter-clockwise) has the suction on the left. Make sure that you verify your orientation when looking at the pump. LH Counter Clockwise    |     RH Clockwise Also don't forget there are no UL/FM listed "left hand rotation" diesel engines available on the market.

Diesel Fuel Tank Size for Fire Pumps

Guidance for the sizing diesel fuel tanks is quite straight forward due to the prescriptive requirements of the code.  Just take your engine HP x 1.10 and the result in gallons is the minimum required diesel fuel storage tank size.  The exact code reference from NFPA 20 (2010 edition) is provided below: 11.4.2* Fuel Supply Tank and Capacity.* Fuel supply tank(s) shall have a capacity at least equal to 1 gal per hp (5.07 L per kW), plus 5 percent volume for expansion and 5 percent volume for sump. A.11.4.2 The quantity 1 gal per hp (5.07 L per kW) is equivalent to 1 pint per hp (0.634 L per kW) per hour for 8 hours. Where prompt replenishment of fuel supply is unlikely, a reserve supply should be provided along with facilities for transfer to the main tanks. How the committee arrived at these simplified guidelines is as follows.  First, lets look at the conditions for when we expect the fire pump to run: Quarterly Refilling of the Fuel Tank (approx 12-weeks) A weekly t