RO Membrane End Cap and Connector Specifications
These RO membrane end cap and connector specifications cover the ATD (anti-telescoping device) end caps and interconnectors used to finish and join industrial spiral-wound elements.
- TypeATD end cap
- MaterialABS / Noryl
- RoleAnti-telescoping
- Used onIndustrial sizes
What the End Cap and Connector Do
The end cap is an ATD — anti-telescoping device — fitted to each end of an industrial element. Under pressure, feed flow pushes the wound layers forward; the ATD cap braces them so the element cannot “telescope” and tear. The connector (interconnector or coupler) joins one element’s central tube to the next in a pressure vessel and seals the joint with O-rings.
For the basics, see what an ATD cap is. Household elements (1812, 2521) are not built with ATD end caps; these parts are used on industrial 4040 and 8040 elements.
End Cap & Connector Specifications
Typical specifications for ATD end caps and connectors. Exact dimensions are set by the element model and confirmed per order.
| Property | Typical specification |
|---|---|
| Components | ATD end cap; interconnector / coupler; O-rings |
| Material | ABS, Noryl (PPO) or PP, depending on application |
| End-cap function | Anti-telescoping support at each element end |
| Connector function | Joins central tubes element-to-element and seals the joint |
| Sizing | Matched to element model (mainly 4040, 8040) |
| Sealing | O-rings on the connector / tube interface — [confirm size] |
| Quantity per element | Two end caps (one each end) on industrial elements; none on household |
| Also known as | ATD cap, end cap, interconnector, coupler |
Matching End Caps and Connectors
Match the ATD cap and connector to the element model and the central-tube interface, and confirm the O-ring sizes for a reliable seal. Get the connector or O-ring wrong and elements will not seat or seal correctly in the vessel — a problem that only appears once the system is pressurised.
Use the element size reference to identify the size, confirm the matching central tube, and check incoming parts in incoming inspection.
Match to your build
- End cap to element model
- Connector to central-tube interface
- Correct O-ring sizes
- Two caps per industrial element
- None on household elements
End Caps Protect the Element Under Pressure
The ATD cap and connector are what let an element survive real operating pressure and connect into a system.
Telescoping
Without a correct ATD cap, pressure pushes the layers forward and tears the element.
Leaking Joints
The wrong connector or O-ring lets feed and permeate mix at the element joint.
Poor Fit
An off-size cap or connector stops elements seating correctly in the vessel.
Need ATD end caps and connectors?
Tell us your element sizes and vessel system — we’ll supply end caps, connectors and O-rings matched to your build.
End Cap & Connector FAQ
What is an ATD cap on an RO membrane element?
An ATD (anti-telescoping device) cap is the end cap fitted to each end of an industrial element. It braces the wound layers against the forward push of feed pressure so the element cannot telescope and tear.
What does the connector do?
The connector, or interconnector, joins the central tube of one element to the next inside a pressure vessel and seals the joint with O-rings, so permeate stays separate from feed across the series of elements.
How many end caps does an element have?
Industrial elements use two end caps — one at each end. Small household elements such as 1812 and 2521 are not built with ATD end caps.
How do I choose the right end cap and connector?
Match them to the element model and the central-tube interface, and confirm the O-ring sizes. Use the element size reference to identify the size, then confirm the exact parts for your vessel system.