AS-Schneider’s E Series Valves and Manifolds can withstand extreme temperature

On Aug 29, 2016

Direct mount manifolds for pressure and differential pressure transmitter equipped with flange connections according to DIN EN 61518 / IEC 61518.

Direct mount manifolds for pressure and differential pressure transmitters are normally protected against excess warming from hot process media through correspondingly long impulse lines. Nevertheless, many users have requested that the manifolds and their flange connection to the transmitter also easily withstand higher temperatures. The E Series Valves and Manifolds by AS-Schneider are available upon request with sealing made of graphite. Thus they can be readily used up to 550 degrees Celsius – significantly more than required by the standards.

With graphite, it is different: The carbon does not show any appreciable deformation even with extreme temperatures thus providing a durable, leakage-free flange connection. As in PTFE packing, graphite shows an intentional flow behaviour which results from the mechanical clamping of the two flange halves during mounting. Compared to the PTFE sealing, however, the graphite exhibits no further significant deformation even under extreme temperatures, thus ensuring a permanent, leak-free flange.

Manifolds with PTFE sealing are clearly at a disadvantage when used at high temperatures: The plastic becomes very soft at high temperatures causing the pressure of the process medium to press it into the available cavities.

The international standard EN 61518 / IEC 61518 describes the flange connection between the manifolds and the pressure transmitters. Here, the temperature limits of these connections are described, among other things: This is 80 degrees Celsius for PTFE sealing and 120 degrees Celsius for graphite sealing. “There are many users who require significantly higher temperature limits than 120 degrees Celsius for their manifolds”, describes Markus Häffner, Head of Design & Development at the industrial valve manufacturer AS-Schneider. AS-Schneider supplies the E Series Valves and Manifolds with either PTFE or graphite sealing. The former are clearly at a disadvantage when used at high temperatures, explains Häffner. PTFE becomes very soft at high temperatures causing the pressure of the process medium to press the plastic into the existing cavities.

With graphite, it is different: The carbon does not show any appreciable deformation even with extreme temperatures thus providing for a durable, leakage-free flange connection.

AS-Schneider