Engineering plastics

PVC (Rigid, Type 1)

Also: polyvinyl chloride, rigid PVC, uPVC, PVC-U, unplasticized PVC, Type 1 PVC, Type I Grade 1 PVC, normal-impact PVC, Type 2 PVC (high-impact), CPVC (chlorinated PVC), PVC cell class 12454, expanded PVC foam board

Type 1 PVC is rigid, unplasticized PVC: cheap, stiff, flame-resistant and acid-proof, for tanks, ducts and piping. Good to about 60 °C; never laser cut it.

ASTM D1784 (rigid PVC and CPVC compounds; cell class 12454 is the old Type I Grade 1)ASTM D1785 (Schedule 40, 80 and 120 PVC pipe)NSF/ANSI 61 and NSF/ANSI 14 (potable water and plastics piping, listed products)UL 94 V-0 (typical for rigid sheet)

Sourcing PVC parts or stock?

Attach a drawing (PDF or STEP) or describe the part; a U.S. shop that fits quotes it.

At a glance

PVC (Rigid, Type 1) typical properties
Density	1.4 g/cm³ (0.051 lb/in³)
Tensile strength	48-55 MPa (7.0-8.0 ksi)
Yield strength	About 45-52 MPa (6.5-7.5 ksi) tensile yield; many data sheets list only the tensile strength
Hardness	Rockwell R 110-120 (Shore D 80-85)
Elongation	20-80% at break
Modulus of elasticity	2.6-3.0 GPa (0.38-0.44 Msi) tensile
Thermal	Tg about 80-85 °C (176-185 °F); amorphous, decomposes rather than melting; continuous service about 60 °C (140 °F); HDT about 70 °C (158 °F) at 1.82 MPa; CPVC to about 93 °C (200 °F)
Composition	Polyvinyl chloride, (C2H3Cl)n, unplasticized, about 57% chlorine by weight, with heat stabilizers, lubricants and pigment; Type 2 adds an impact modifier

Typical values, Type 1 (normal impact) gray extruded or pressed sheet and extruded rod, 23 °C (73 °F). Confirm against the mill certificate and the purchase spec.

MachinabilityGood: Machines well with sharp tools and short chips. Keep it cool with air or water: overheating scorches the surface and releases hydrogen chloride, which also corrodes machine tools. Notch-sensitive, so radius inside corners.
WeldabilityExcellent: Solvent cement (THF, MEK and cyclohexanone based) makes pipe joints rated with the pipe. Sheet is hot-gas and extrusion welded with PVC rod into tanks, hoods and ducts. Adhesives bond it well.
FormabilityGood: Line-bends and thermoforms well with heat, and pipe can be hot-bent. It is too stiff and notch-sensitive to form cold except for thin sheet.
Corrosion resistanceExcellent: Resists most acids (including hydrochloric and dilute to moderately concentrated sulfuric), alkalis, salts, oxidizing solutions such as hypochlorite, and aliphatic hydrocarbons. Attacked by ketones, esters, aromatic and chlorinated solvents, and by strong oxidizing acids when hot or concentrated. Chalks slowly in sunlight.

Rigid PVC is polyvinyl chloride without plasticizer. About 57% of its weight is chlorine, which makes it dense (1.4 g/cm3), inherently flame-retardant and self-extinguishing, and highly resistant to the acids, alkalis, salts and oxidizing solutions that attack most metals. Type 1 (normal impact, usually gray) has the best chemical resistance and stiffness, and it is the default material for chemical process piping, plating and etching tanks, fume ducts and scrubbers, and water-treatment parts. Type 2 adds an impact modifier for tougher sheet at some cost in chemical and heat resistance.

PVC is easy to fabricate. Pipe and fittings join with solvent cement, sheet is hot-gas welded with PVC rod into tanks and hoods, sheet line-bends and thermoforms, and stock machines cleanly into valve bodies, manifolds and fittings. It is stiff for a commodity plastic (about 2.8 GPa) and dimensionally stable, with low water absorption and thermal expansion about half that of polyethylene.

Heat is its limit. The glass transition is around 80 °C (176 °F), so continuous service stops at about 60 °C (140 °F), and pressure ratings fall well before that. Overheated PVC decomposes and releases hydrogen chloride, which is why it must never be laser cut or torched, why it is machined cool, and why molding it needs corrosion-resistant equipment. For hot water and warmer chemical service, CPVC extends the range to about 93 °C (200 °F); beyond that, polypropylene, PVDF or PTFE-lined steel.

Heat treatment

Not heat treated. Stress relieve heavily machined or welded parts at about 60-70 °C (140-160 °F), well below Tg, and cool slowly; overheating risks warping and decomposition.

Tempers and conditions

Type 1 (normal impact, gray)
Type 2 (high impact)
CPVC (chlorinated, higher temperature)
Clear PVC
White and colored sheet
Expanded (foam) PVC board
Schedule 40 and 80 pipe and fittings

Stock forms

Sheet and plate
Rod and bar
Pipe, tube and fittings
Duct
Angles and profiles
Welding rod
Foam board

Relative cost

Tier 1 of 5. A commodity plastic, comparable to HDPE per pound; CPVC costs noticeably more. Fabrication labor, not material, usually drives tank and duct cost.

Typical applications

Chemical process piping, valves and fittings
Plating, etching and pickling tanks
Fume hoods, exhaust ducts and scrubbers
Water and wastewater treatment components
Wet benches and lab fixtures
Electrical conduit, boxes and insulating barriers
Machined manifolds, pump parts and valve bodies

Process compatibility

How PVC takes each process, and what to specify. Each process links to its own guide and to the shops that do it.

PVC (Rigid, Type 1) process compatibility
Process	Rating	Notes
CNC Machining	GoodGood	Machines cleanly into valve bodies, manifolds and fittings; keep cutting temperatures low.
CNC Milling	GoodGood	Routes and mills from sheet with sharp carbide; chips are short and easy to clear.
CNC Turning	GoodGood	Fittings, bushings and valve parts from rod; flood with water or use an air blast to stay cool.
Waterjet Cutting	GoodGood	Cold cutting with no risk of decomposition; a good choice for thick plate.
Laser Cutting	Not recommendedNot recommended	Never laser cut PVC: it releases hydrogen chloride gas, which is toxic and forms hydrochloric acid that corrodes the laser optics and machine.
Injection Molding	FairFair	Fittings and housings are molded at volume, but PVC is heat-sensitive and corrosive in the barrel; it needs corrosion-resistant screws and tight temperature control, so few job-shop molders run it.
FDM 3D Printing	Not recommendedNot recommended	Degrades and gives off hydrogen chloride at printing temperatures. Print a stand-in and machine PVC.
Powder Coating	Not recommendedNot recommended	Cure ovens run far above the 70 °C heat deflection temperature; PVC warps and decomposes. Buy colored sheet.
Vibratory Finishing	FairFair	Deburrs small machined parts; fabrications are deburred by hand.
Bead Blasting	FairFair	Gives a matte surface for appearance or bonding; use low pressure.

Design and sourcing tips

State Type 1 or Type 2 on the drawing: Type 1 for chemical resistance and stiffness, Type 2 only where impact matters more than chemistry.
Check chemical and temperature together. PVC pipe and tank ratings are published at 23 °C (73 °F) and fall steeply above it; above about 60 °C (140 °F), use CPVC, polypropylene or PVDF.
Keep laser cutting, torch cutting and open-flame heating out of the process; rout, saw or waterjet instead.
For welded tanks, agree the welding method and a leak or spark test with the fabricator; hot-gas welds are weaker than the sheet and are designed for.
Allow for thermal expansion of about 50-60 um/m·K on long pipe runs and ducts, with expansion loops or joints.

Frequently asked questions

Can PVC be laser cut?: No. Heating PVC with a laser releases hydrogen chloride gas, which is toxic to breathe and turns into hydrochloric acid with moisture, corroding the laser optics, motion system and exhaust. Laser shops ban it. Cut PVC by routing, sawing or waterjet.
What is the difference between Type 1 and Type 2 PVC?: Type 1 is unmodified rigid PVC with the best chemical resistance, stiffness and heat resistance; it is the normal choice for tanks, piping and chemical parts. Type 2 contains an impact modifier, so it is tougher but slightly weaker and less heat- and chemical-resistant. ASTM D1784 now uses cell classes instead, with 12454 matching the old Type I Grade 1.
What temperature can PVC handle?: Rigid PVC is generally limited to about 60 °C (140 °F) in service, and its pressure rating drops steadily above 23 °C (73 °F). It softens toward its glass transition around 80 °C (176 °F). CPVC, with extra chlorine, is rated to about 93 °C (200 °F) and is the usual choice for hot water and warm chemical lines.
Is PVC UV resistant?: Moderately. Rigid PVC chalks and slowly loses impact strength in sunlight, although its stiffness and pressure capability change little. Outdoor pipe and sheet should be painted or made from UV-stabilized formulations.

Processes that commonly use it

Injection Molding Overmolding

Related materials

HDPE (High-Density Polyethylene)ABS Acrylic (PMMA)Polycarbonate (PC)PTFE (Teflon)

Where to verify these values

ASTM D1784 and D1785
Rigid PVC sheet producer data (Simona, Vycom)
Uni-Bell PVC Pipe Association Handbook of PVC Pipe Design and Construction
ASTM D638 and D648 test methods

PVC (Rigid, Type 1)

Type 1 PVC is rigid, unplasticized PVC: cheap, stiff, flame-resistant and acid-proof, for tanks, ducts and piping. Good to about 60 °C; never laser cut it.

At a glance

PVC (Rigid, Type 1) typical properties
Density	1.4 g/cm³ (0.051 lb/in³)
Tensile strength	48-55 MPa (7.0-8.0 ksi)
Yield strength	About 45-52 MPa (6.5-7.5 ksi) tensile yield; many data sheets list only the tensile strength
Hardness	Rockwell R 110-120 (Shore D 80-85)
Elongation	20-80% at break
Modulus of elasticity	2.6-3.0 GPa (0.38-0.44 Msi) tensile
Thermal	Tg about 80-85 °C (176-185 °F); amorphous, decomposes rather than melting; continuous service about 60 °C (140 °F); HDT about 70 °C (158 °F) at 1.82 MPa; CPVC to about 93 °C (200 °F)
Composition	Polyvinyl chloride, (C2H3Cl)n, unplasticized, about 57% chlorine by weight, with heat stabilizers, lubricants and pigment; Type 2 adds an impact modifier

Typical values, Type 1 (normal impact) gray extruded or pressed sheet and extruded rod, 23 °C (73 °F). Confirm against the mill certificate and the purchase spec.

MachinabilityGood

Machines well with sharp tools and short chips. Keep it cool with air or water: overheating scorches the surface and releases hydrogen chloride, which also corrodes machine tools. Notch-sensitive, so radius inside corners.

WeldabilityExcellent

Solvent cement (THF, MEK and cyclohexanone based) makes pipe joints rated with the pipe. Sheet is hot-gas and extrusion welded with PVC rod into tanks, hoods and ducts. Adhesives bond it well.

FormabilityGood

Line-bends and thermoforms well with heat, and pipe can be hot-bent. It is too stiff and notch-sensitive to form cold except for thin sheet.

Corrosion resistanceExcellent

Resists most acids (including hydrochloric and dilute to moderately concentrated sulfuric), alkalis, salts, oxidizing solutions such as hypochlorite, and aliphatic hydrocarbons. Attacked by ketones, esters, aromatic and chlorinated solvents, and by strong oxidizing acids when hot or concentrated. Chalks slowly in sunlight.

Typical applications

Chemical process piping, valves and fittings

Plating, etching and pickling tanks

Fume hoods, exhaust ducts and scrubbers

Water and wastewater treatment components

Wet benches and lab fixtures

Electrical conduit, boxes and insulating barriers

Machined manifolds, pump parts and valve bodies

Process compatibility

How PVC takes each process, and what to specify. Each process links to its own guide and to the shops that do it.

PVC (Rigid, Type 1) process compatibility
Process	Rating	Notes
CNC Machining	GoodGood	Machines cleanly into valve bodies, manifolds and fittings; keep cutting temperatures low.
CNC Milling	GoodGood	Routes and mills from sheet with sharp carbide; chips are short and easy to clear.
CNC Turning	GoodGood	Fittings, bushings and valve parts from rod; flood with water or use an air blast to stay cool.
Waterjet Cutting	GoodGood	Cold cutting with no risk of decomposition; a good choice for thick plate.
Laser Cutting	Not recommendedNot recommended	Never laser cut PVC: it releases hydrogen chloride gas, which is toxic and forms hydrochloric acid that corrodes the laser optics and machine.
Injection Molding	FairFair	Fittings and housings are molded at volume, but PVC is heat-sensitive and corrosive in the barrel; it needs corrosion-resistant screws and tight temperature control, so few job-shop molders run it.
FDM 3D Printing	Not recommendedNot recommended	Degrades and gives off hydrogen chloride at printing temperatures. Print a stand-in and machine PVC.
Powder Coating	Not recommendedNot recommended	Cure ovens run far above the 70 °C heat deflection temperature; PVC warps and decomposes. Buy colored sheet.
Vibratory Finishing	FairFair	Deburrs small machined parts; fabrications are deburred by hand.
Bead Blasting	FairFair	Gives a matte surface for appearance or bonding; use low pressure.

Design and sourcing tips

State Type 1 or Type 2 on the drawing: Type 1 for chemical resistance and stiffness, Type 2 only where impact matters more than chemistry.

Check chemical and temperature together. PVC pipe and tank ratings are published at 23 °C (73 °F) and fall steeply above it; above about 60 °C (140 °F), use CPVC, polypropylene or PVDF.

Keep laser cutting, torch cutting and open-flame heating out of the process; rout, saw or waterjet instead.

For welded tanks, agree the welding method and a leak or spark test with the fabricator; hot-gas welds are weaker than the sheet and are designed for.

Allow for thermal expansion of about 50-60 um/m·K on long pipe runs and ducts, with expansion loops or joints.

Frequently asked questions

Can PVC be laser cut?

No. Heating PVC with a laser releases hydrogen chloride gas, which is toxic to breathe and turns into hydrochloric acid with moisture, corroding the laser optics, motion system and exhaust. Laser shops ban it. Cut PVC by routing, sawing or waterjet.

What is the difference between Type 1 and Type 2 PVC?

Type 1 is unmodified rigid PVC with the best chemical resistance, stiffness and heat resistance; it is the normal choice for tanks, piping and chemical parts. Type 2 contains an impact modifier, so it is tougher but slightly weaker and less heat- and chemical-resistant. ASTM D1784 now uses cell classes instead, with 12454 matching the old Type I Grade 1.

What temperature can PVC handle?

Rigid PVC is generally limited to about 60 °C (140 °F) in service, and its pressure rating drops steadily above 23 °C (73 °F). It softens toward its glass transition around 80 °C (176 °F). CPVC, with extra chlorine, is rated to about 93 °C (200 °F) and is the usual choice for hot water and warm chemical lines.

Is PVC UV resistant?

Moderately. Rigid PVC chalks and slowly loses impact strength in sunlight, although its stiffness and pressure capability change little. Outdoor pipe and sheet should be painted or made from UV-stabilized formulations.