Connecting Low Side Compensation Leg; Open Tank Installation; Closed Tank Installation - ABB S26 Series Operating Instruction

6 Connecting low side compensation leg on a DP transmitter with one seal.
Differential pressure transmitters with a single remote seal
element are used for liquid level installations. The seal element
is connected using the procedure applicable to the type of seal
element. The connection requirements for the low side
depends on whether the tank is open to atmosphere or closed
(pressurized or evacuated). Make the low side connection as
described below.

6.1 Open Tank Installation

The low side of the transmitter must be vented to atmosphere
for open tank installations. Be sure there are no plastic shipping
plugs or other restrictions in the low side flange ports. Connect
the seal element using the procedure applicable to the element
type. Refer to the Connecting the Remote Seals section.

6.2 Closed Tank Installation

Before connecting the seal element to the tank fitting,
determine whether a wet or dry compensating leg is required
on the low side of the transmitter. Refer to the Locating the
Transmitter and Remote Seals section.
The transmitter is shipped with the vent/drain plug located near
the top of the low side flange. In this position the valve permits
venting of entrapped gas (normally air) when a wet (liquid filled)
compensating leg is required. If a dry leg is required, remove
the bolts and rotate the low-side flange 180° so that the vent/
drain screw is positioned at the bottom of the flange to permit
draining of condensate from the primary cavity. Re-tighten the
bolts to a torque of 20 ft-lb.
After properly locating the vent/drain screw, connect the low
side to the compensating leg, and connect the seal element
using the procedure applicable to the element type. Refer to
the Connecting the Remote Seals section.
38 OI/S26-EN Rev. B | 2600T Series Pressure transmitters