Selection guide compiled by cBallast. 3-page PDF; the full content is on this page.
Brand
Roxtec
Subject
Cable transits and seals
Document type
Selection guide
Reference
2026 edition
Issued
2026-10-18
Pages
3
Format
Web page and PDF
How the Roxtec system composes: weld/bolt frames by opening count, RM modules whose peelable Multidiameter layers adapt one block to a span of cable diameters, blank modules and the compression unit, EMC/galvanised/stainless executions, and the spare-capacity habit that makes transits a project asset instead of a bottleneck.
A transit is a kit of three decisions
Layer
What you choose
Stocked examples
Frame
Opening count/arrangement and material — bolted or welded into the wall, floor or cabinet
Multidiameter is the trick: each half-module carries concentric peelable layers — strip layers until the printed window matches the cable OD, and one stocked module size seals dozens of cable types. "WOC" (without core) modules are the solid blanks: they fill unused openings today and become tomorrow's cable routes by swapping to a cored module — no new penetration, no hot work.
Execution choices that follow the wall
Material: AISI316 frames for exposed, washdown and corrosive sites; galvanised (GH) for dry industrial walls. The frame must suit the structure it welds or bolts into.
Ratings follow the assembly — fire class, water/gas tightness and pressure are certified for frame + modules + compression as a system; mixing foreign blocks voids the lot.
EMC versions bond cable screens through the transit for EMI-critical rooms — specified at order, not retrofitted.
Versus glands: one multi-cable wall opening with a transit replaces a plate of single glands wherever cables arrive in numbers or will grow — and transits forgive cable replacement without re-drilling.
The spare-capacity habit
Projects that fill every opening on day one buy a second transit within two years. The planning rule: size the frame for ~30 % spare openings filled with WOC blanks, record the layer-strip chart per cable in the handover docs, and keep a small stock of cored modules and blanks — around 240 Roxtec line items are stocked under the brand page for exactly these top-ups. Frame + module list + compression unit quote as one package within 24 hours; send the cable schedule (type, OD, count, growth margin) and the composition comes back engineered.
Frequently asked questions
How do Multidiameter modules fit different cable sizes?
Each half-block is built of concentric peelable layers: strip layers until the remaining bore matches the cable's outside diameter per the printed window (an RM 60 spans roughly 24–54 mm). One module size thereby covers a whole range of cables.
What does WOC mean in a Roxtec reference?
Without core — a solid blank module. Blanks seal unused openings at full rating and are the cheap way to build spare capacity: swap a blank for a cored module when the new cable arrives.
Can I mix module brands inside a Roxtec frame?
No — the certification (fire, water, gas, pressure) applies to the tested system of frame, modules, stayplates and compression unit together. Foreign blocks or improvised fillers void the rating of the whole transit.
Transit or cable glands — when does each win?
Glands win for one or two cables through a cabinet wall. Transits win where cables arrive in bundles, will be added to, or where a certified fire/water barrier is required across many cables in one opening — ships' practice that industrial plants adopted for good reasons.
How much compression does the frame need?
Whatever brings the compression unit to its stated travel/torque once modules and stayplates are packed — hence the pre-compression tool in stock. Under-compressed transits leak; over-packing with the wrong module count prevents proper wedging at all.