Recently Got Big Water had a discussion on double diamond placement of portable tanks which evolved into a low level strainers/jet siphon discussion.
Member Roger Sill was unfamiliar with a low level strainer manufactured by Firovac. This strainer was not included in a test result done by Got Big Water. However, Charles Clark from Colerain Township responded to Mr. Sill concerning the experience they have had with this Firovac strainer with jet siphon. Following is the response from Charles Clark:
"The TFT low level strainer/jet siphon using a one inch orifice consumes 364 GPM from a fire pump when transferring water from one dump tank to another @ 150 psi. This can be confirmed by consulting published charts of flows from various orifice sizes at various pressures. The Belmont Tanker Task Force in eastern Ohio did a study (spring 2016) of jet siphon efficiency. They tested the TFT jet siphon. along with several others. They used a truck scales to very precisely measure the net water transferred by each jet siphon. Most jet siphons use a one inch orifice. A few jet siphons use 3/4 inch orifices. Only one low level strainer/jet siphon in the study used a 1/2 inch orifice. That unit is produced by Firovac (manufacturer of vacuum tankers). It transferred a net flow of 807 GPM from dump tank to dump tank while consuming only 91 GPM from the fire pump @ 150 psi.
This stingy use of water from the fire pump is as revolutionary as the advent of dump tanks years ago. It is said that the use of a dump tank is equal to adding another tanker to the rotation. I think switching to jet siphons that only use 91 GPM each from a pumper makes it possible to eliminate a pumper ofter set up to run jet siphons.
This fall we conducted a tanker shuttle drill in which a 1250 GPM pumper was able to push 1,060 GPM back a lane to a mock fire scene. No jet siphon pumper was needed because only 192 GPM was needed to run two Firovac jet siphons. Transferring with two TFT jet siphons would have consumed (recirculated) 724 GPM leaving only 526 GPM available to pump to the fire scene. Eliminating the need for a jet siphon pumper is critical for water supply operations in a single traffic lane."
Any discussion on this topic is encouraged.