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Key to nameplate data – See additional information below:
Design ambient temperature range “Ta”
Unless differently agreed with the customer, can be:
-20°C ≤ Ta ≤ +40°C: STD temperature range for all type of pumps
5.0 Description and Theory of Operation
The PULSAlarm® leak detection system utilizes a two-layer PTFE diaphragm, coupled to
a pressure switch.
The system is initially primed by filling the void within the detection assembly and between
the diaphragm layers with a barrier fluid. The setup process then bleeds excess fluid from
between the diaphragm layers until they are in close contact. The system operates as
follows:
During normal pump operation, the two layers of the PTFE diaphragm bear
directly against one another, and there is no pressure generated between the two
layers. The sensing system monitors the space between the layers, which will
remain at zero pressure as long as the diaphragm layers remain undamaged.
In the event of a failure of either layer of the diaphragm, liquid will enter the space
between the two layers. This liquid will be either the hydraulic oil (if the rear layer
fails) or the pumped fluid (if the front layer fails). As the pump operates, this liquid
will generate pressure between the layers of the diaphragm that will then be
transferred outwards by the barrier fluid. This fluid will create pressure against the
pressure switch. This switch has a trip point of 20 psi (1.37 bar). When this
pressure is reached the switch will operate. The pressure system requires a more
complex setup procedure, however once operational it should require no further
maintenance or operator interaction.
The output of the switch on either system (both normally closed and normally
open connections are available) can then signal the failure of the diaphragm. It
is recommended that the pump be stopped in the event a leak is detected.
Immediate attention to the problem, followed by cleanup and appropriate
maintenance, will avoid further damage to the pump.
The barrier fluid used with the pressure-based system should be chosen for compatibility
with the process and environmental conditions. The fluid chosen should have as low a
viscosity as possible to aid in priming the system. Water can be used, and ethylene or
propylene glycol can be added for corrosion and temperature protection. Thin oils such
as silicone oil or mineral oil can also be used. Liquids of higher viscosity will extend the
time required to properly prime the system. Thinner liquids will allow for faster setup.
NOTE: Pulsafeeder supplies as standard low viscosity silicone oil.
System identification is noted on the switch cover nameplate, and also on your
Pulsa Series pump nameplate.