I did hundreds of these tests over thirty-one years in the southeast before I retired from FM Global. Some good memories and interesting stories. Once I had the opportunity, in the 1990s, to witness operation of an Underwriters steam pump still in use. It was at an ancient coke plant (the coal product, not the beverage) on a bluff overlooking Birmingham. I could go on and on, but one little thing I'll pass along here. When you test the automatic start, don't do it from the pump room. There is an orifice plate in the copper sensing line. It looks like a union fitting. The purpose of it is to dampen out pressure fluctuations that could cause false starts. If the 3/32 in. hole is plugged up by debris, etc. the pressure drops on the controller side when you open the valve at the controller, and the pump would start as it normally does. But in event of fire pressure would not pass through the orifice plate to tell the controller to start. Lesson: always do the automatic start by dropping pressure on the plant side of the orifice plate.
I’ve thought about that before, however if you drop the pressure on the sensing line at the controller transducer the pump will obviously automatically start (or at least it should… if it doesn’t you have bigger problems). Once the pump starts running, IF one or both of those restricted orifices on the sensing line are plugged you would know due to the fact that the sensing line gauge will read no pressure; furthermore if you hit “stop” on the controller the fire pump will either not stop due to the cut out pressure not being met, or the pump will stop and then the moment you release the stop button it will start up again due to the pressure in the sensing line being below that of the cut-in pressure. Either way, you will know that one or more of the restricted orifices are plugged and need to be cleaned. So I wouldn’t really worry about dropping pressure downstream of the ground face unions/sensing line check valves with the 3/32” R.O’s. Testing the pump the way you are suggesting (dropping pressure downstream of the RO’s on the system side) will prove the R.O’s are plugged if the fire pump doesn’t automatically start when dropping the pressure. The other reason I wouldn’t normally test the pump using the method you mentioned is because most fire pump installations don’t have a means of draining pressure downstream of the RO’s while the fire pump discharge control valve is in the closed position. Since the fire pump sensing line must be tied in between the fire pump discharge check and the fire pump discharge control valve, the only way of dropping pressure downstream of the sensing line restricted orifices would be to leave the fire pump discharge control valve open which we typically don’t like to do either you are now exposing everything downstream of the fire pump to water hammer- which really shouldn’t be a problem since under normal circumstances this is what will actually happen but still… we don’t usually like to just let the fire pump rip and intentionally leave the FP discharge open.
During the NFPA starts did you run them for the minimum time to ensure no carbon buildup? What was that minimum time? 10 minutes? 30 minutes? Good video, thanks.
What is the closed loop setup? Pump discharge to pump suction? Or supply tank back to supply tank? Was the pitot tube test a demonstration? Great good team work. I don't think the 3 year pitot test is required if the supply tank loop is used, unless of course there is a question about pump degradation or instrument issue, e.g., bad data. Correct?
Yeah. Pull the lid and the rotating assembly and repack it properly. There’s no easy way. There’s the right way and the wrong way. Don’t be the guy who gets a packing puller and pulls a couple rows out and stuffs a few new ones in there.
I did hundreds of these tests over thirty-one years in the southeast before I retired from FM Global. Some good memories and interesting stories. Once I had the opportunity, in the 1990s, to witness operation of an Underwriters steam pump still in use. It was at an ancient coke plant (the coal product, not the beverage) on a bluff overlooking Birmingham.
I could go on and on, but one little thing I'll pass along here. When you test the automatic start, don't do it from the pump room. There is an orifice plate in the copper sensing line. It looks like a union fitting. The purpose of it is to dampen out pressure fluctuations that could cause false starts. If the 3/32 in. hole is plugged up by debris, etc. the pressure drops on the controller side when you open the valve at the controller, and the pump would start as it normally does. But in event of fire pressure would not pass through the orifice plate to tell the controller to start. Lesson: always do the automatic start by dropping pressure on the plant side of the orifice plate.
I’ve thought about that before, however if you drop the pressure on the sensing line at the controller transducer the pump will obviously automatically start (or at least it should… if it doesn’t you have bigger problems). Once the pump starts running, IF one or both of those restricted orifices on the sensing line are plugged you would know due to the fact that the sensing line gauge will read no pressure; furthermore if you hit “stop” on the controller the fire pump will either not stop due to the cut out pressure not being met, or the pump will stop and then the moment you release the stop button it will start up again due to the pressure in the sensing line being below that of the cut-in pressure. Either way, you will know that one or more of the restricted orifices are plugged and need to be cleaned.
So I wouldn’t really worry about dropping pressure downstream of the ground face unions/sensing line check valves with the 3/32” R.O’s. Testing the pump the way you are suggesting (dropping pressure downstream of the RO’s on the system side) will prove the R.O’s are plugged if the fire pump doesn’t automatically start when dropping the pressure. The other reason I wouldn’t normally test the pump using the method you mentioned is because most fire pump installations don’t have a means of draining pressure downstream of the RO’s while the fire pump discharge control valve is in the closed position. Since the fire pump sensing line must be tied in between the fire pump discharge check and the fire pump discharge control valve, the only way of dropping pressure downstream of the sensing line restricted orifices would be to leave the fire pump discharge control valve open which we typically don’t like to do either you are now exposing everything downstream of the fire pump to water hammer- which really shouldn’t be a problem since under normal circumstances this is what will actually happen but still… we don’t usually like to just let the fire pump rip and intentionally leave the FP discharge open.
very nice execution of fire pump electric
Would you please recommend us with a dealer for the same machine here? Please
Here is a lil tip for y,all. Make sure the pump room doors open out and not in. Also chock the doors fully open before starting any testing.
Nice job sir
During the NFPA starts did you run them for the minimum time to ensure no carbon buildup? What was that minimum time? 10 minutes? 30 minutes? Good video, thanks.
What is the closed loop setup? Pump discharge to pump suction? Or supply tank back to supply tank? Was the pitot tube test a demonstration? Great good team work. I don't think the 3 year pitot test is required if the supply tank loop is used, unless of course there is a question about pump degradation or instrument issue, e.g., bad data. Correct?
Pump discharge to suction is the closed loop test.
Do you know the easiest way to repack a fire pump
Yeah. Pull the lid and the rotating assembly and repack it properly. There’s no easy way. There’s the right way and the wrong way. Don’t be the guy who gets a packing puller and pulls a couple rows out and stuffs a few new ones in there.