Off-Line Threaded Connection Seal (S26Tt) - ABB S26 Series Operating Instruction

5.6 Off-line Threaded Connection Seal (S26TT)

The off-line threaded remote seal connects directly to a process pipe via the NPT connection in the lower housing. Connections
for 1/4, 1/2, 3/4, 1, and 1-1/2 in. process piping are available. In addition to the process connection, mechanical support for the
weight of the seal may be required, especially for the 1/4 and 1/2-inch pipe sizes.
These elements are available with a flushing connection in the lower housing. The connection provides a 1/4 in. NPT port into the
cavity around the seal diaphragm to permit flushing to remove trapped solids, when necessary. The flushing connection also
provides a means of checking calibration without disconnecting the element. A gate or ball valve installed in the process line near
the seal element connection allows the process to be isolated and calibration pressure can then be applied via the flushing
connection. Use of a gate or ball type valve avoids restricting the process line during normal operation, not a gasket.
Connect the seal element to the process pipe at the NPT connection in the end of the lower housing.
If the element has a flushing connection, connect a flushing line with appropriate valving to the 1/4 in. NPT connection in the side
of the lower housing.
Figure 20: Off-line threaded connection diaphragm seal
S26TT can be supplied with different kinds of bolts: stainless steel AISI 316, carbon steel or alloy steel (NACE compliant)
For any other detailed information regarding S26TT seals such as pressure limits, vacuum service recommendations, process
temperature limits, temperature effects and configuration, please refer to product datasheet.
Size (thread)
1/4 in. NPT
1/2 in. NPT
3/4 in. NPT
1 in. NPT
1 1/2 in. NPT
Ø D
GASKET
THREADED
PROCESS
CONNECTION
Dimensions mm (in) for S26T
D (dia) Q
109.2 (4.3) 53.3 (2.1)
109.2 (4.3) 53.3 (2.1)
109.2 (4.3) 63.5 (2.5)
109.2 (4.3) 63.5 (2.5)
109.2 (4.3) 63.5 (2.5)
2600T Series Pressure transmitters | OI/S266-EN Rev. B 21
FLUSHING
CONNECTIONS
(two 1/4 in. NPT-f)