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Irrigation Pipe. CPVC. Pressure Rating Standards. Rated pressure – amount of pressure (PSI) pipe can handle Depends on pipe material, pipe’s diameter and wall thickness Decreases significantly when water temps exceed 73 F. POLYVINYLCHLORIDE (PVC). Semi-rigid plastic.
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Pressure Rating Standards • Rated pressure – amount of pressure (PSI) pipe can handle • Depends on pipe material, pipe’s diameter and wall thickness • Decreases significantly when water temps exceed 73 F
POLYVINYLCHLORIDE (PVC) • Semi-rigid plastic
POLYVINYLCHLORIDE (PVC) • Iron pipe size (IPS) – the common standard that pipe is sized to fit couplers • Plastic irrigation pipe (PIP) – less common
CLASSIFICATIONS OF PVC SCHEDULE PVC • Pipe pressure ratings change with pipe diameter because wall thickness always the same
CLASSIFICATIONS OF PVC SCHEDULE PVC • Sch. 40: white • Sch. 80: gray (thicker) • Sch 40 PVC 1” pipe has a rating of 450 PSI • Sch 40 PVC 4” pipe has a rating of 220 PSI
CLASSIFICATIONS OF PVC SDR PVC All diameters have same pressure rating • Class 200 • All CL 200 pipes are 200 psi • Class 160 • All CL 160 pipes are 160 psi
CLASSIFICATIONS OF PVC SDR PVC • Standard dimension ratio-pressure rated • Wall thickness is adjusted to the pipe diameter • The larger the pipe, the thicker the wall
PIPE DIMENSIONS • OD controlled – inside diameter is changed to meet the wall thickness requirements • Used on PVC so that all pipe sizes of different thickness will fit in couplers
PVC LABEL • NSF – National Sanitary Foundation approved for potable water • PVC 1120 – pipe material • PSI at 73 F – pressure rating
CPVC • Beige color • Plumbing applications • Fittings not interchangeable with PVC • Requires CPVC glue
POLYETHYLENE PIPE (PE) • Resistant to sunlight deterioration • Drip irrigation, some sprinklers • Connected by inserts or couplers • Flexibility adapts to freezing conditions
SIZING PIPE too large • Economical • Smaller pipe costs less
SIZING PIPE too small • Operational efficiency • When pipe is sized too small, water speed (velocity) is too fast • Lose pressure to friction loss
Pipe Damage • Water hammer –force of water coming to abrupt stops • Eventually cracks tees and elbows from repeated force
Pipe Damage Water hammer • Reinforce tees on large pipe • Open valves slowly • Properly sized pipes to reduce velocity
Solvent Welding • Cleaner • Dirt and debris • Primer (purple stuff) • Dirt and debris • Chemically softens plastic • Often used instead of cleaner • Cement (solvent weld) • Chemically welds plastic together
Solvent Welding • Square cut • Bevel edge on >4” pipe
Solvent Welding • Prime • Outside of pipe • Inside of fitting
Solvent Welding • Cement • Outside of pipe • Inside of fitting
Solvent Welding • Insert pipe • Quarter turn • Hold for 30 seconds • Wipe off excess
Solvent Welding • Set and cure time varies • Temperature and time • Colder takes longer • 1” pipe cures in 15 minutes
PVC Components Slip fittings • Glue together • Socket (S) • “female” • Spig (Sp) • “male” • Usually the pipe end
PVC Components Threaded fittings • Screw together • Female pipe threads (FPT) • Male pipe threads (MPT)
PVC Components Threaded fittings • Teflon tape on constant pressure fittings • Apply clockwise
Adapter • Changes connection type
Reducer bushing • Reduces connection size • Fits into coupler
Coupler • Connects pipe