OAR 340-073-0060
Distribution Boxes, Drop Boxes, and Diversion Valves: Pipe Materials and Construction
(1)
Effluent Sewer Pipe: The effluent sewer must be constructed with materials in conformance with state building sewer standards. The effluent sewer pipe must have a minimum diameter of 3 inches. When the septic tank is fitted with an effluent filter, the minimum nominal diameter of piping may be reduced to 1-1⁄4 inches.(2)
Underdrain pipe. Underdrain pipe must meet or exceed the requirements for Class 125 PVC pressure pipe as identified in ASTM Specification D 2241. The pipe and fittings must be marked as required by ASTM Specification D 2241. The underdrain pipe must be perforated in accordance with subsection (4)(d) of this rule or with 1⁄4-inch slots cut halfway through the pipe at 4 inches center to center.(3)
Polyvinyl chloride (PVC) pressure transport pipe, pressure manifolds, and pressure lateral pipe and fittings must meet or exceed the current requirements for Class 160 PVC 1120 pressure pipe as identified in ASTM Specification D 2241. The pipe and fittings must be marked as required by ASTM Specification D 2241. For pipe diameters of 1 inch or less, the minimum pressure rating is 200 pounds per square inch (psi). For pipe diameters greater than 1 inch, the minimum pressure rating is 160 psi.(4)
Distribution and Header Pipe and Fittings.(a)
Polyethylene distribution pipe in 10 foot lengths and header pipe in lengths of 10 feet or greater must meet the current ASTM Specification F 405. Pipe and fittings must also pass a deflection test withstanding 350 pounds per foot without cracking or collapsing using the method in ASTM 2412. Pipe used in absorption facilities must be heavy duty. Markings must meet requirements in ASTM F 405.(b)
Polyvinyl chloride (PVC) distribution and header pipe and fittings must meet the most current ASTM Specification D 2729. Pipe and fittings must pass a deflection test withstanding 350 pounds per foot without cracking or collapsing using the method found in ASTM 2412. Markings must meet requirements in ASTM Specification D 2729.(c)
Polyethylene smooth wall distribution and header pipe in 10-foot length and fittings must meet the most current ASTM Specification F 810. Pipe and fittings must also pass a deflection test of 350 pounds per foot without cracking or collapsing by using the method found in ASTM 2412. Markings shall meet the requirements in ASTM Specification F 810, Section 9.(d)
The three types of plastic pipe described above must have two rows of holes spaced 120 degrees apart and 60 degrees on either side of a center line. For distribution pipe, a line of contrasting color must be provided on the outside of the pipe along the line furthest away and parallel to the two rows of perforations. Durable ink markings must cover at least 50% of the pipe. Markings may consist of a solid line, letters, or a combination of the two. Intervals between markings must not exceed 12 inches. The holes of each row may not be more than 5 inches on center and must have a minimum diameter of 1⁄2 inch.
Source:
Rule 340-073-0060 — Distribution Boxes, Drop Boxes, and Diversion Valves: Pipe Materials and Construction, https://secure.sos.state.or.us/oard/view.action?ruleNumber=340-073-0060.