Groth 1660A - Manual (Page 3)

Page 3 of 16
Figure 1: Tank Installation – Safety Equipment
summarized in Table 1 below. Each type is
available with either a standard O-Ring seat or
the optional mechanically tensioned FEP film
seat. The FEP film diaphragm provides a tight
seal capable of meeting current Clean Air Act
fugitive emission levels and is recommended
for cryogenic applications.
Table 1
1660A Series Pilot Operated Valve Models
Model P V Vacuum Operation
1660A X Not Available
1661A X X Direct actuated
1662A X Pilot actuated
A variety of material options are available in
addition to the standard constructions listed in
the Bill of Materials on page 13. Direct
actuated vacuum protection utilizes tank
vacuum applied to the main valve actuator
diaphragm support plate to provide pallet lift.
The non-adjustable vacuum setting varies
according to valve size and materials of
construction, and the valves typically achieve
full flow capacity at 2 Oz/Sq In.
The nameplate shows the basic information
that is listed on each relief valve. See Fig. 2.
Figure 2: Nameplate
Each application must be reviewed to ensure
material compatibility of all metal and soft
goods components with the service
conditions. The pallet assembly and wetted
components are aluminum or 316 SS and
may be upgraded to Hastelloy C or other
alloys for severely corrosive service.
Diaphragms, gaskets and bushings are FEP
film or PTFE. O-Rings can be specified as
Buna-N, EPDM, FFKM or FKM. Sense tubing
is 316SS, and it is available in PVDF for
severely corrosive service.
The pilot valve is set at the factory to comply
with the specification on the purchase order.
The range of adjustment will depend on the
spring installed and will be stamped on the
pilot nameplate. The pressure setting may be
changed within the design range either while
on line or in a service shop. Observe the