Polycab HMS FRLS uPVC Conduit Pipe – Heavy Mechanical Stress, 20 to 50 mm Outside Diameter, IS 9537 Part 3

Polycab HMS FRLS uPVC Conduit Pipe is a rigid uPVC FRLS (flame retardant, low smoke) conduit of the heavy mechanical stress class, made to IS 9537 (Part 3) in five sizes - 20, 25, 32, 40 and 50 mm outside diameter - and supplied in 3 m lengths (codes CPI0320001 to CPI0350001). It is the conduit that protects house wires and cables in a building; the heavy class is meant for conduit cast into RCC slabs and floors, laid under floor screeds, or run where it can be knocked, stepped on or crushed.

Polycab India Limited is India's largest manufacturer of wires and cables, with 27 manufacturing facilities, 4,300+ authorised distributors, 2,00,000+ retailers and an export presence in 84 countries (polycab.com, October 2026). Polycab is ISO 9001:2015 certified and makes its conduits to IS 9537 (Part 3) and its conduit fittings to IS 3419, from what its catalogue calls "the highest grade of waterproof and fire-resistant polymers". Jai Enterprises supplies the Polycab conduit range from Bhilai and Raipur all over Chhattisgarh - Bhilai, Raipur, Durg, Korba, Bilaspur, Raigarh, Jagdalpur, Kanker, Ambikapur and every other district - and across India; price on request.

Is this the right one for you?

Check these four things before you order:

• You are running house wires or cables inside a rigid conduit - concealed in walls, ceilings or slabs, or on the surface.
• The conduit is cast into an RCC slab, laid in a floor or exposed to knocks and loads - the heavy mechanical stress class is made for that.
• Flame-retardant, low-smoke (FRLS) conduit is wanted or specified for the building.
• You know the size: 20 mm and 25 mm for most lighting and socket circuits, 32, 40 and 50 mm for sub-mains, risers and bunches of circuits (see the size list below).

Polycab HMS FRLS uPVC Conduit Pipe - pick your size

Each size has its own page with the product code, inside diameter, pack and matching fittings:

• Polycab HMS FRLS uPVC Conduit Pipe 20 mm - code CPI0320001, minimum inside diameter 15.8 mm, standard pack 75 x 3 m (225 m)
• Polycab HMS FRLS uPVC Conduit Pipe 25 mm - code CPI0325001, minimum inside diameter 20.6 mm, standard pack 50 x 3 m (150 m)
• Polycab HMS FRLS uPVC Conduit Pipe 32 mm - code CPI0332001, minimum inside diameter 26.6 mm, standard pack 25 x 3 m (75 m)
• Polycab HMS FRLS uPVC Conduit Pipe 40 mm - code CPI0340001, minimum inside diameter 34.4 mm, standard pack 25 x 3 m (75 m)
• Polycab HMS FRLS uPVC Conduit Pipe 50 mm - code CPI0350001, minimum inside diameter 43.2 mm, standard pack 15 x 3 m (45 m)

At a glance

• Price: on request - call +91 9340081159
• Product: Polycab HMS FRLS uPVC Conduit Pipe
• Type: rigid plain conduit for electrical wiring (IS 9537 Part 3)
• Mechanical stress class: Heavy Mechanical Stress (HMS)
• Fire performance: FRLS - flame retardant, low smoke
• Sizes: 20, 25, 32, 40 and 50 mm outside diameter
• Length: 3 m per length
• Standard pack: 75 x 3 m (20 mm), 50 x 3 m (25 mm), 25 x 3 m (32 and 40 mm), 15 x 3 m (50 mm)
• Product codes: CPI0320001 (20 mm) to CPI0350001 (50 mm)
• Colours: black, ivory, grey and red in the Polycab colour chart (availability by size and series on enquiry)
• Standard: IS 9537 (Part 3); Polycab is ISO 9001:2015 certified

Specifications by size

• 20 mm: code CPI0320001; outside diameter 20 mm (tolerance -0.3 mm); minimum inside diameter 15.8 mm; standard pack 75 x 3 m (225 m)
• 25 mm: code CPI0325001; outside diameter 25 mm (tolerance -0.4 mm); minimum inside diameter 20.6 mm; standard pack 50 x 3 m (150 m)
• 32 mm: code CPI0332001; outside diameter 32 mm (tolerance -0.4 mm); minimum inside diameter 26.6 mm; standard pack 25 x 3 m (75 m)
• 40 mm: code CPI0340001; outside diameter 40 mm (tolerance -0.4 mm); minimum inside diameter 34.4 mm; standard pack 25 x 3 m (75 m)
• 50 mm: code CPI0350001; outside diameter 50 mm (tolerance -0.5 mm); minimum inside diameter 43.2 mm; standard pack 15 x 3 m (45 m)
• Dimension basis: minimum inside diameters are the IS 9537 Part 3 values for the heavy class as printed in the Polycab B2B all-products catalogue (2025)
• Matching fittings: Polycab circular, deep and fan boxes, bends, tees, elbows, couplers, reducers and saddles, made to IS 3419

Why choose Polycab HMS FRLS uPVC Conduit Pipe

• Flame retardant, low smoke (FRLS) compound - resists the spread of flame and gives off less smoke, for safer wiring in homes and public buildings
• Heavy Mechanical Stress class to IS 9537 (Part 3) - the thickest wall and smallest bore of the three classes, for conduit cast into RCC slabs and floors, laid under floor screeds, or run where it can be knocked, stepped on or crushed
• Waterproof, fire-resistant polymer - the catalogue describes Polycab uPVC conduits as made "only from the highest grade of waterproof and fire-resistant polymers"
• Five sizes, 20 to 50 mm outside diameter - one series for lighting, power, sub-mains and risers
• 3 m lengths in standard packs - 75 lengths of 20 mm down to 15 lengths of 50 mm per pack, easy to count and order
• Matching Polycab fittings to IS 3419 - circular and deep boxes, fan boxes, bends, tees, elbows, couplers, reducers and saddles

Choosing the size and class, and installing it

Size: the number of wires a conduit can take depends on the wire size and the length and bends of the run - follow the conduit-capacity table you work to (for example the one in IS 732) or the consultant's drawings. In typical house wiring, 20 mm carries lighting circuits and 25 mm socket and power circuits.

Class: heavy mechanical stress conduit suits conduit cast into RCC slabs and floors, laid under floor screeds, or run where it can be knocked, stepped on or crushed. For the other classes see the series list below.

Installing: join lengths with Polycab couplers (in concealed work the joint is usually made permanent with PVC solvent cement), make bends with a bending spring of the right size or with Polycab bends and elbows, fix surface runs with saddles at regular spacing, and leave a draw wire in long runs.

Where it is used

• Conduit cast into RCC roof and floor slabs
• Floor runs under screeds and tiles
• Industrial buildings, workshops and plant rooms
• Basements, car parks and runs exposed to knocks

The Polycab conduit pipe series

• Polycab LMS FRLS uPVC Conduit Pipe - light mechanical stress, FRLS, codes CPI0120001 to CPI0150001
• Polycab MMS FRLS uPVC Conduit Pipe - medium mechanical stress, FRLS, codes CPI0220001 to CPI0250001
• Polycab HMS FRLS uPVC Conduit Pipe (this page) - heavy mechanical stress, FRLS, codes CPI0320001 to CPI0350001
• Polycab LHSFT MMS Conduit Pipe - medium mechanical stress, LHSFT series, codes CPI0420002 to CPI0450002
• Polycab LHSFT HMS Conduit Pipe - heavy mechanical stress, LHSFT series, codes CPI0720002 to CPI0750002

Related products

• Polycab PVC circular box terminal (1 way) and tee (3 way) - junction boxes for 20 and 25 mm conduit
• Polycab deep circular boxes and fan boxes - for boxes cast into slabs
• Polycab PVC conduit coupler, reducer and inspection bend
• Polycab Green Wire+ house wire and Suprema E-beam house wire - the wires that go inside
• All uPVC conduits and all conduit fittings

Frequently asked questions

What does HMS FRLS mean?

HMS is the heavy mechanical stress class of IS 9537 Part 3, and FRLS means flame retardant, low smoke - the conduit compound resists the spread of flame and gives off less smoke in a fire.

What sizes does Polycab HMS FRLS uPVC Conduit Pipe come in?

20, 25, 32, 40 and 50 mm outside diameter, each in 3 m lengths: 20 mm = CPI0320001 (75 lengths per pack), 25 mm = CPI0325001 (50 lengths per pack), 32 mm = CPI0332001 (25 lengths per pack), 40 mm = CPI0340001 (25 lengths per pack), 50 mm = CPI0350001 (15 lengths per pack).

What is the difference between LMS, MMS and HMS conduit?

The three mechanical stress classes of IS 9537 Part 3. They share the same outside diameter, but the wall gets thicker from light to heavy: a 20 mm conduit has a minimum inside diameter of 17.4/16.9/15.8 mm (light/medium/heavy). Light is for surface runs, medium for concealed wiring in walls and ceilings, heavy for slabs, floors and places where the conduit can be crushed or knocked.

Which fittings go with it?

Polycab makes circular boxes (terminal, angle, through, tee, 4-way, U, Y and H types), deep circular boxes, fan boxes, slip and inspection bends, round and inspection tees and elbows, couplers, reducers, space bar saddles and saddle straps - mostly in 20 and 25 mm, with deep boxes, couplers, reducers and long bends in the larger sizes. They are listed under conduit fittings on this site.

What colours are available?

The Polycab catalogue colour chart shows black, ivory, grey and red; tell us the colour with your enquiry and we will confirm what is in stock.

Where can I buy Polycab HMS FRLS uPVC Conduit Pipe in Chhattisgarh?

From Jai Enterprises, Bhilai and Raipur, which supplies Polycab conduits and fittings across Chhattisgarh - Korba, Bilaspur, Raigarh, Jagdalpur, Kanker, Ambikapur and every other district - and across India. Call +91 9340081159 with the size, quantity and delivery location and we will confirm the price, availability and lead time.

How to order

Supplied by Jai Enterprises, Bhilai and Raipur, to every district of Chhattisgarh and across India. To request a price for Polycab HMS FRLS uPVC Conduit Pipe, call +91 9340081159 or send an enquiry from this page with the size, the quantity (lengths or packs) and the delivery location, and we will confirm the price, stock and lead time.