Emerson 350, 250 operation manual Insulation against extreme heat/cold, When insulating gages

4.3Insulation (against extreme heat/cold)

Magtech strongly recommends that an experienced Magtech Technician do insulation of the magnetic level gages at the factory with externally mounted transmitters.

If Cryogenic “Hard Skin” cold service type insulation is required, it must be done at the factory due to the custom “TUBE in TUBE” design necessary for removal of the transmitter if needed.

If insulation is going to be done in the field, then the following guidelines MUST be followed:

1.Flexible type insulation jackets (NOT HARD SKIN) are required and must be installed around the mag-gage chamber only. DO NOT cover the LTM sensor tube, as this may burn up the sensor and possibly the electronics.

2.After the insulation jacket is installed, the LTM sensor tube must be remounted at its factory- preset distance from the mag-gage chamber and must be parallel to the chamber as well (small cut-outs in the jacket are required to re- attach the transmitter properly).

3.Make sure that the 0% and 100% (4/20mA) marking on the sensor tube are re-aligned at the centers of the process connections.

(When insulating gages):

Magtech level transmitters have a maximum operating temperature of 300 F. When insulating a mag-gage and transmitter assembly in HOT service, keep the transmitter OUTSIDE the insulating material. Special blankets for this type of insulation are available from Magtech, and recommended to guarantee proper insulation. For further information consult the factory.