Description: Plan 66A is an external drain with an external
pressure transmitter to detect high level leak rates. Normally
for Arrangement 1 single seals. Pressure port and drain are separated by
a gland bushing with an additional gland bushing on atmosphere side.
Objective: Detect seal failure early and minimize leakage past gland.
Typically used on single seals in remote locations and critical processes.
Advantages: More efficient directing leakage to a drain than Plan 66B.
Description: Plan 66B
is an external drain
with an orifice plug and an
external pressure transmitter to
detect high level leak rates on
atmosphere side of seal, utilizing a
single gland bushing. Normally for
Arrangement 1 single seals.
Objective: Same as Plan 66A.
Advantages: Can easily adapt to
most existing seal glands.