Medium and Heavy Wall Tubing

S3(n) Medium Wall Halogen Free Heat Shrink Tube

Halogen free medium wall polyolefin tubing with 3:1 and 4:1 shrink for insulating sealing and protecting cable to 36 kV

Operating temperature: -55 to 110°C
Minimum fully recovery temperature: 125°C
Shrink ratio: 3:1 & 4:1
Halogen-free, RoHS compliant
Single or Dual wall optional
Standard Color: Black, Other colors optional

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S3(n) Medium Wall Halogen Free Heat Shrink Tube manufactured by UPM Heat Shrink

S3(n) · Medium and Heavy Wall Tubing

Product Overview

What S3(n) Does

Medium wall halogen-free polyolefin shrink tubing,with or without adhesive liner.Excellent insulation,mechanical protection and sealing of low voltage power cable joints and terminations.

Halogen free medium wall polyolefin tubing with 3:1 and 4:1 shrink for insulating sealing and protecting cable to 36 kV It is manufactured by Dalian United Polymer Material Co., Ltd. in Dalian China where radiation cross linking extrusion and molding are all performed in house under one quality system.

Key Benefits

Halogen free and RoHS compliant for enclosed and public infrastructure
3:1 and 4:1 ratios that cover a wide diameter range from one stock size
Operating range from -55 to 110 °C which exceeds most cable jacket ratings
Adhesive lined option that seals against water at cable jacket repairs and joints
Black as standard with other colours available for phase identification

Who It Is For

Who Benefits Most from S3(n)

The buyers and site teams this product was designed around

Tunnel Metro and Building Services Contractors

Halogen free is mandatory where a cable fire would fill an enclosed space with corrosive smoke.

Data Centre and Hospital Electrical Teams

Sensitive equipment and evacuation routes make halogen free the default specification.

LV and MV Jointing Crews

Medium wall tubing is the workhorse layer for jacket repair joint sealing and general insulation.

Panel Builders and OEMs

Insulating and sealing cable entries and internal connections inside assemblies.

Problems It Solves

Problems This Product Removes

Every one of these is a failure mode we have seen on real networks

Halogenated Smoke Is a Life Safety Issue in Enclosed Routes

S3(n) is halogen free and RoHS compliant so it can be specified in tunnels shafts metro stations and public buildings.

A 2:1 Tube Will Not Cover an Irregular Profile

3:1 and 4:1 shrink ratios let one size span from a large connector down to a small cable diameter.

Thin Wall Tubing Tears During a Duct Pull

Medium wall gives real mechanical protection where a thin wall would abrade through.

Sealing Needs Adhesive but Not Every Position Does

Single wall and adhesive lined dual wall are both offered so the same product family covers sealed and unsealed positions.

Application Scenarios

Where It Is Used

LV Cable Joint Sealing

Outer protection and sealing over a completed 1 kV joint.

Cable Jacket Repair

Covering a damaged outer sheath section.

Busbar and Connector Insulation

Insulating exposed connections inside enclosures.

Cable Entry Sealing

Sealing where cable passes through a gland plate or bulkhead.

Marine and Rail Cabling

Halogen free routes where smoke toxicity is regulated.

Technical Data

Specifications and Dimensions

Test methods and requirements taken directly from the manufacturing specification

Technical Data

Property	Test Method	Requirement
Tensile Strength	ASTM D2671	≥12 MPa
Ultimate Elongation	ASTM D2671	≥300%
Heat Aging (136°C/168h) Tensile Strength Ultimate Elongation	ASTM D2671	≥10 MPa ≥200%
Water absorption (23°C/24h)	ASTM D2671	≤0.5%
Low-temperature flexibility (-55°C/4h)	ASTM D2671	No cracking
Heat shock (200°C/4h)	ASTM D2671	No cracking, dripping or flowing
Dielectric strength	ASTM D2671	≥15 kV/mm
Volume resistivity	ASTM D2671	≥1.0×1014Ω·cm
Copper corrosion	ASTM D2671	No corrosion

Dimensions

Size S3(n)	As supplied(mm) Inner diameter D (min.)	After recovered (mm) Inner diameter d (max.)	Wall thickness t (nom.)	Standard length (m/pcs)
8/2	8	2	1.8(with glue)	1.0/1.22
9/3	9	3	1.9(with glue)	1.0/1.22
12/4	12	4	2.2(with glue)	1.0/1.22
16/5	16	5	2.5(with glue)	1.0/1.22
19/6	19	6	2.4	1.0/1.22
22/6	22	6	2.4	1.0/1.22
25/8	25	8	2.5	1.0/1.22
28/6	28	6	2.9	1.0/1.22
33/8	33	8	2.9	1.0/1.22
35/12	35	12	2.6	1.0/1.22
40/12	40	12	2.8	1.0/1.22
45/13	45	13	2.9	1.0/1.22
55/16	54	16	3	1.0/1.22
65/19	65	19	3	1.0/1.22
75/22	75	22	3	1.0/1.22
85/25	85	25	3	1.0/1.22
95/25	95	25	3.2	1.0/1.22
105/30	105	30	3.2	1.0/1.22
115/34	115	34	3.2	1.0/1.22
130/36	130	36	3.2	1.0/1.22
140/42	140	42	3.3	1.0/1.22
160/50	160	50	3.4	1.0/1.22
175/58	175	58	3.4	1.0/1.22
200/65	200	65	3.5	1.0/1.22
230/75	230	75	3.5	1.0/1.22
260/85	260	85	3.5	1.0/1.22
300/100	300	100	4	1.0/1.22

S3(n) construction and dimension diagram — S3(n) as supplied and fully recovered dimensions. D is the supplied inner diameter d is the recovered inner diameter and t is the recovered wall thickness.

CROSS REFERENCE · Tyco-Raychem: MWTM /BSTS/ SST-M

Manufacturing and Quality

How It Is Made and Checked

Compounding extrusion radiation cross linking expansion and test all under one roof in Dalian

01
Compounding

Base polyolefin antioxidants flame retardants and functional fillers are mixed to a recipe held under our own formulation control rather than bought as a masterbatch.
02
Extrusion

The compound is extruded to the required wall and diameter. Co extruded products form two or three layers in a single pass so no interface can trap air.
03
Radiation Cross Linking

Electron beam irradiation creates the cross linked network that gives the material its shape memory. This step is what makes the product heat shrinkable.
04
Expansion

The cross linked part is heated expanded to its supplied diameter and cooled under tension so the expanded shape is locked in until heat is applied again.
05
Test and Inspection

More than 90 percent of product performance tests are carried out in our own laboratory including tensile elongation heat aging dielectric strength and tracking resistance.
06
Packing and Traceability

Each batch carries a production record so a delivered part can be traced back to its compound lot and process parameters.

Extrusion and irradiation workshop at the UPM Heat Shrink factory in Dalian China — Extrusion and processing workshop in Dalian. Line side inspection stations let an operator check wall thickness and concentricity without stopping the run.

Certification

ISO 9001:2015

Quality management system

IATF 16949:2016

Automotive quality management

ISO 14001:2015

Environmental management

ISO 45001:2018

Occupational health and safety

GJB 9001C-2017

Defence quality management

UL 224 E341796

Extruded insulating tubing

CE / RoHS

European conformity and restricted substances

CCS / ABS / DNV

Marine classification society approvals

Comparison

How S3(n) Compares

An honest comparison so you can rule this product in or out quickly

Product	Wall Class	Fire Behaviour	Typical Use
S3(n)	Medium wall	Halogen free	Enclosed routes public buildings
S3(nh)	Heavy wall	Halogen free	Enclosed routes needing more mechanical protection
S3	Medium wall	Flame retardant	Marine offshore wet and underground
S3(h)	Heavy wall	Flame retardant	Marine offshore heavy duty

Use Guide

How to Select and Install S3(n)

The sequence our engineers walk customers through on every first installation

01
Measure the Largest and Smallest Diameter

The tube must slide over the largest point and recover tight onto the smallest. That ratio decides whether you need 3:1 or 4:1.
02
Decide If You Need Adhesive

Choose adhesive lined dual wall wherever water must be excluded. Choose single wall for pure insulation inside a dry enclosure.
03
Cut to Length with Allowance

Allow at least 25 mm of overlap onto sound material at each end and remember the tube shortens slightly as it recovers.
04
Clean and Abrade

Wipe the surface and lightly abrade a glossy jacket so the adhesive keys properly.
05
Shrink from One End

Work steadily from one end to the other so air escapes ahead of the heat.
06
Check the Adhesive Bead

On dual wall a continuous bead at both ends confirms the seal.

FAQ

S3(n) Frequently Asked Questions

The questions buyers ask before they place an order

What does halogen free mean in practice

The compound contains no chlorine bromine fluorine or iodine so a fire produces no corrosive hydrogen halide gas. That matters in tunnels metro stations data centres and hospitals.

What is the difference between S3(n) and S3

S3(n) is halogen free. S3 is flame retardant and formulated for wet and underground environments including marine vessels offshore platforms shipyards and harbours. Both are medium wall.

When do I need 4:1 instead of 3:1

When the object being covered has a large step such as a connector on a small cable. A 4:1 ratio covers a wider diameter span from one stock size.

Can it be used on a 36 kV cable

Yes for sealing and mechanical protection up to 36 kV. It is not a stress control or primary MV insulation layer. Use C102 and C101 for those functions.

Is the adhesive suitable for a polyethylene jacket

Yes. The standard adhesive bonds to polyethylene PVC and cross linked polyethylene jackets. Abrade a glossy surface first for the best bond.

What colours are available

Black is standard. Other colours are available on a production run for phase identification or customer branding.

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S3(nh)