Nov . 02, 2026 01:33 Back to list

How to Select a Double Sphere Union Type Rubber Joint for Your Piping Layout

This guide helps procurement teams assess the Double Sphere Union Type Rubber Joint by connection construction, nominal size, face-to-face length, and listed movement values. It is suited to buyers specifying a union-type joint in sizes from 15 mm to 80 mm and matching the joint’s movement range to the piping layout.

Illustration for reference; see the product page for actual photos and specifications.

Connection construction and material requirements

Nominal size, installation length, and movement range

A double sphere union type rubber joint should be selected from the connection arrangement, nominal size, installation length, and movement required by the piping layout. The available union-type model uses a polarized rubber body, nylon cord fabric lining, and a union made from malleable iron or steel. Its listed sizes run from 15 mm (1/2 inch) through 80 mm (3 inches).

Start with the connection and materials

The union connection is the first screening point for a replacement or new piping assembly. The joint uses a malleable iron or steel union, so the purchase specification should identify the required union material and confirm that it matches the connected pipe and installation details.

The body and lining also matter during specification. This model combines a polarized rubber body with nylon cord fabric lining. Include those construction details in the inquiry so the supplier is quoting the intended joint, not a similarly named flange-type or single-sphere product.

For a closer look at the product configuration, see the Double Sphere Union Type Rubber Joint.

Match nominal size and face-to-face length

The listed nominal sizes are 15, 20, 25, 32, 40, 50, 65, and 80 mm. The first five sizes, from 15 to 50 mm, have a listed length of 200 mm. The 65 mm and 80 mm sizes have a listed length of 245 mm.

These dimensions give the installation team two items to check before ordering:

the pipe’s nominal size, expressed in millimeters or inches;
the available face-to-face space for the joint length.

Picture a maintenance replacement in a compact pipe run. A size match alone does not establish that the joint will fit between the existing connection points. Measure the installed gap and compare it with the 200 mm or 245 mm length associated with the selected size.

Check movement against the pipe layout

For the listed 15 mm to 80 mm sizes, the axial displacement is 5 to 6 mm. Stretch is listed as 22 mm, compression as 22 mm, and lateral displacement as 22 mm.

Use these values as the movement screen for the purchase specification. A line that needs movement beyond the listed values requires a different design review before this joint is selected. The movement figures should also be considered alongside the actual support arrangement, alignment, and installation space, which the buyer should provide to the supplier.

Which buyer situation fits this model?

This joint suits a buyer who needs a union-type connection and whose pipe size falls within the listed 15 mm to 80 mm range. It is also a practical candidate when the layout can accommodate a 200 mm or 245 mm joint length and the required axial, stretch, compression, and lateral movement remains within the listed values.

The model is less suitable for a specification that requires a flanged end, a nominal size above 80 mm, or movement outside those listed figures. In those cases, the connection style or size range does not match this union-type selection.

Purchase checklist

Send the supplier these details with the inquiry:

Nominal pipe size and inch equivalent.
Required union material, malleable iron or steel.
Available face-to-face installation length.
Required axial, stretch, compression, and lateral movement.
Pipe layout information showing the joint location and connected equipment.

Before requesting a quotation, measure the installed gap and record the pipe size, connection arrangement, and expected movement so the supplier can review the 200 mm or 245 mm length and the listed 22 mm movement values against your layout.

The people

About the author

Richard Garcia

Richard Garcia is a Supply Chain Manager for Hebei Honest Industrial Group, responsible for ensuring the smooth flow of materials and products from our factory to customers worldwide. He expertly manages logistics, inventory control, and vendor relationships.

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Richard has 12 years of experience in international trade and is knowledgeable about import/export regulations. He often provides commentary for our market reports, detailing factors impacting lead times and pricing. He is focused on optimizing our supply chain for increased efficiency and responsiveness, making sure our customers receive products on time and within budget.

The company

Hebei honest industrial group Co.,Ltd.

Hebei Honest Industrial Group Co., Ltd. is a professional manufacturer and supplier of industrial valves and accessories, wires and cables. As a group company, we are committed to developing long-term cooperative relationships with customers and continuously improving our production processes and processing technologies.…

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