Packing Glands for Instrumentation Leads

Conestoga USA, Inc. designs and fabricates packing glands (wire feed-throughs) for the power transmission industry. These fittings are used to provide a fluid-tight means of bringing instrumentation wires out of large gear boxes, turbine housings or other pressurized machinery. Because they are often used in inaccessible locations the gland must be leak proof. Conestoga offers glands in many sizes, and made with various wire configurations to suit multiple applications.

The following catalog pages show the current selection of our standard glands. Space does not allow the presentation of the numerous modifications to these standard designs which have been made to satisfy individual customer requests. If the glands described on these pages are not suitable for your needs, please contact us to discuss your requirements.

Use of Conestoga USA Packing Glands

The Gland Cap and Cartridge Assembly (Insert, Grommet, Follower and Screw) are removed from the gland assembly and the Gland Body is threaded into the machine housing. The instrumentation leads coming from the machine housing are then fed through the Gland Body, the Insert, the Grommet, the Follower and the Cap.

If necessary, the Cartridge Assembly is broken down for ease of wire installation but care should be taken that the leads make a straight passage through the gland, ie: the insert, grommet and follower holes which the wire passes must be concentric or the gland will not assemble properly. The Assembly Screw helps to maintain hole alignment during assembly and the screw head may be gripped with pliers in order to remove the Cartridge Assembly from the Gland Body.

As shipped, the wire holes are blocked off with nylon rods which are removed by the installer as needed. If the installation does not utilize all the available wire holes the nylon rods are left in the unused holes to seal them. For example, a type 306 gland (Figure 2) can be used for one to six wires.

In cases where the sensor leads do not have a free end and the sensor head diameter is larger than the wire diameter, the grommet wire holes are split to allow the wires to be inserted through the side of the grommet (Figure 4).  In this application, the wire holes through the insert and follower are oversize to permit passage of sensor heads up to .270 inch (6.8 mm) diameter, or use inserts and followers of two-piece construction (Figure 5).

After wire installation, the Cartridge Assembly is inserted into the Gland Body, care being taken that the key on the Follower engages the keyway of the Gland Body. When the Cartridge is fully inserted only .12 inchs (3 mm) of the Follower will protrude from the Gland Body.

The Cap is added and tightened against the Follower. Tighten the Cap 1/4 turn past hand tight. Next, the Jam Nut is tightened against the Cap to prevent its becoming loose from vibration or over-tightened from wrench work when conduit is attached to the Cap.

Packing gland
Figure 1.
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Packing gland
Figure 2.
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Packing gland cartridge assembly
Figure 3. "Cartridge Assembly"
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Packing Gland Split Grommet Installation
Figure 4. "Split Grommet Installation"
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Packing Gland Split Grommet Installation
Figure 5.
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Selecting a Gland

To ensure proper selection, ask the following questions:

  • How many wires will the gland be sealing on?
  • What is the actual diameter of the wire that the grommet will be sealing against?
  • What is the size and type of fluid connection needed on the Gland Body?  (example: 3/4 male NPT).
  • What is the size and type of conduit connection needed on the Gland Cap? (example: 1/2 male NPT)


  • All gland bodys, caps, jam nuts and assembly screws are made of 303 stainless steel.
  • The insert and follower are made of 6061 aluminum and are anodized.
  • The grommet is made of fluorocarbon elastomer, 57 durometer. Silicone grommets are available upon request.