Landscape Irrigation Based upon the book Rain Bird Irrigation Design Manual

Types of Pipe Polyethylene – PE Often used in mid-west and east Black Usually barbed fittings Polyvinyl chloride – PVC Most commonly used in So. Cal. White or gray Typically glued and/or threaded fittings

Polyethylene – PE Pipe

Flexible, lightweight Cuts easily with tubing cutters Uses barbed fittings – no glue Can be installed with pipe puller – reduces labor Not shovel- or pocket gopher-friendly

Barbed Fittings

Pipe Puller

PVC Pipe Rigid, fairly lightweight Cuts easily with PVC cutters or saws Chemically welded connections Durable & Buriable Resists shovels and gophers Some UV resistant

PVC Pipe Ratings Divided into two groups Schedule rated (Schedule or Sch) Pressure Rated (Class or Cl) Not UV resistant must be buried or painted

Schedule Rated Pipe Thick walled Same dimensions as iron pipe Used in pressurized main line situations Pressure ratings change as sizes change Schedule 40 (Sch 40) (white) Schedule 80 (Sch 80) (dark gray)

Guaranteed Pressure Rating Remember: pressure rating changes with pipe size & larger diameter pipes sustain less pressure Sch 40 typical for irrigation uses

Schedule 80 Gray plastic Thick walls Threadable Very strong Used as transition from valves to pipe Outside diameter same as white PVC PVC nipples typically Sch 80

Schedule 40 White plastic Thinner walls than Sch 80 3/4” to 1-1/4” as main- or service-line (under pressure) Pipe sizes – based on O.D. – “nominal”

Pressure Rated PVC Pipe 1/2” or 1-1/2” and larger used as service-, or main-line 3/4” and larger used as lateral line Pressure rated instead of schedule rated Which means a uniform pressure rating regardless of size Built-in 2:1 safety factor for surges

Standard Dimension Ratio (SDR-PR) The ratio of wall thickness to O.D. is same throughout each class SDR is a relationship of wall thickness to O.D. = SDR PR = Pressure Rated Outside Diameter Wall Thickness

1120, 1220 – Some Data Code Raw materials and stress 11 = Type 1 & Grade 1 Suitable for irrigation 12 = Type 1 & Grade 2 Suitable for drainage 20 = material tensile strength (in 100s) Material can hold up to 2,000 psi in pulling stress

Pressure Rated PVC Pipe Typically used in landscape irrigation Class 315 (Cl 315) – rated at 315 psi Class 200 (Cl 200) – rated at 200 psi Easily cut - resists damage Strong and durable (*except Cl 125 & Cl 160 – too thin to safely use) Class 160* (Cl 160) – rated at 160 psi Class 125* (Cl 125) – rated at 125 psi

Guaranteed Pressure Rating Pressure stays the same regardless in change of diameter or wall thickness

Pressure Rated PVC Pipe Class 315 Main line or service line — 1-1/2” and larger Lateral line — 1-1/2” and larger Class 200 Lateral line — 3/4” and larger

ASTM American Society for Testing and Materials ASTM D-1785 – tests schedule rated pipe ASTM D-2241 – tests pressure rated pipe Select ONLY PVC produced under ASTM standards

Some Other Stuff “Purple pipe” – for reclaimed water Olson Tubing ® or Funny Pipe ® – swing joints

A Review of a Few Terms City water main Underground pipe – under streets, alleys, etc. Supplies water to houses and business Static pressure dependent upon Distance from pumping station Age of pipe Time of day Number of customers on the line

A Review of a Few Terms Water service Between the home or business and the water meter Under constant pressure Can be: Polyethylene galvanized steel Type L copper or PVC – Sch 40 or Class 315 Covered by at least 18” of soil

A Reminder When replacing a metal water service (galvanized or copper) for a plastic one MAKE SURE THE HOUSE’S ELECTRICAL SYSTEM IS GROUNDED!

A Review of a Few Terms Irrigation service line – from point of connection (POC) Under constant pressure Can be: Polyethylene galvanized steel Type L copper or PVC – Sch 40 or Class 315 Covered by at least 18” of soil

Still More Terms (ad nauseam) Lateral line Carries water from the irrigation valves to the sprinkler heads Under pressure when valves are open Typically PVC Class 315 for 1/2” Class 200 for 3/4” and larger Covered by at least 12” of soil

Priceless Information The industry standard for the maximum safe velocity in feet per second (fps) through pipe Plastic pipe – not to exceed 5 fps Metal pipe – not to exceed 7.5 fps

Still More Terms (ad nauseam) Threads on pipe and fittings Female threads – on inside of fittings Male threads – on outside of pipe or fittings

Fittings

PVC Slip Fittings Sch 40 PVC White plastic Slip by slip fittings (SxS) glued aka (socket x socket) configuration I.D. of fitting matches O.D. of corresponding pipe size

PVC Slip Fittings Common Sch 40 fittings Tee SxSxS divides flow of water two ways Coupling SxS Connects two pieces of pipe 90º Elbow (Ell) SxS Changes direction of water

PVC Slip x Thread Fittings Schedule 40 Slip by thread fittings (SxT) or (SxMIPT or SxFIPT) Glued joint and threaded joint on same fitting Threaded ends same size and type as metal pipe threads – tapered thread I.D. of fitting matches O.D. of corresponding PVC pipe size

PVC Slip x Thread Fittings SxT 90º Elbow (Ell) Female Adapter SxT Male Adapter SxT 90º Street Elbow SxT Tee SxSxT

PVC Thread x Thread Fittings Schedule 40 Thread by thread fittings (TxT) (MIPT or FIPT) Two threaded joints on same fitting Threaded ends same size as metal pipe threads I.D. of fitting matches O.D. of corresponding pipe size Not commonly used in PVC

PVC Pipe Nipples Pipe threaded at both ends PVC nipples typically Sch 80 Used to make transition from thread to glue TxT Close Nipple TxT Nipple

Slip Fix An irrigation miracle! Used to repair broken PVC lines Typically SxS Telescopes to extend

Compression Fittings Used to connect PVC to metal pipe Slips over and tightens with compression washers Compression Couplings Compression Tee