Data Sheet

Large ET and ED Valves
D103554X012
Product Bulletin
51.1:ET/ED (Large)
March 2015
4
ET High Temperature Seal
(HTS1)
The High Temperature Seal (HTS1) is available for the
ET only and is required for applications where the
service temperature exceeds 232_C(450_F). This seal
is available for all sizes and trims of the ET and allows
the valve to be used in temperatures up to 316_C
(600_F). See table 3 for temperature limits and figure
2.
The High Temperature Seal is used in place of the
standard plug seal ring and seat ring seal ring. This seal
employs an identical seal ring as the standard ET, but
with the addition of an antiextrusion ring, backup
ring, and retaining ring. At temperatures above 232_C
(450_F) the elastomer material the seal ring is
constructed from becomes soft and can be damaged
due to an extrusion process that could occur when the
valve plug is moved inside the cage. The purpose of
the antiextrusion ring and backup ring is to prevent
the seal ring from being extruded.
Figure 2. Typical Fisher Large ET Valve with HTS1 Seal (Flow Down)
X0216-1
A
B
VIEW A
RETAINING RING
ANTI-EXTRUSION
RING
CAGE
BACKUP RING
PLUG
PLUG SEAL RING
VIEW B
RETAINING RING
ANTI-EXTRUSION
RING
VALVE
BODY
BACKUP RING
SEAT
RING
SEAT RING
SEAL RING