Pulsafeeder PULSAlarm - Manual (Page 6)

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1.2 PULSAlarm Reagent Head
The PULSAlarm leak detection
reagent head assembly consists of
reagent head, leak detection
diaphragm, suction and discharge
check valves, bleed port, and optional
switch and gauge. The reagent head,
diaphragm, suction and discharge
check valves are the only parts of the
pump to contact the process liquid;
consequently, maintenance is critical
to pump performance
Figure 1 – reagent head
A SEALED SYSTEM MUST BE MAINTAINED AT ALL TIMES DURING PUMP OPERATION ,
WHETHER LEAK DETECTION IS REQUIRED OR NOT . I F THE PROPER LEVEL OF
VACUUM , BETWEEN 10 IN AND 26 IN . (250 MM TO 650 MM ) H G , OR A SEALED
PRESSURE SYSTEM IS NOT PRESENT , DECREASED FLOW AND / OR DIAPHRAGM
DAMAGE WILL OCCUR . P LEASE NOTE THAT THE FACTORY SETPOINT FOR
ACTUATION OF THE VACUUM SWITCH IS 6 IN (152 MM ) H G ( VACUUM ) OR 5 PSIG
( PRESSURE ).
1.3 PULSAlarm Leak Detection Diaphragm
Double, or sandwiched, PTFE diaphragms are sealed at their peripheries to an intermediate metal spacer
ring. The space between the diaphragms is sealed so that the diaphragm functions as does a standard
single diaphragm. For the vacuum system, the space between the diaphragms is evacuated of air to
produce a vacuum. For the pressure system, the space between the diaphragms is filled with a small
amount of fluid. This space is connected to an adjustable electrical switch (optional) that actuates in
response to loss of vacuum or buildup of pressure resulting from rupture of either or both diaphragms.
Switch operation can be used to perform any external function, typically to signal an alarm or turn off the
pump. Refer to Figures 1 and 2.
During installation, ensure that adequate space is available at the front of the reagent head
assembly to allow for service of both the pressure switch and the diaphragm assembly.