Pipe Marking Standards

Containers and Piping Marked in accordance with OSHA Standard ... 

E 3] First, the 3-D plant is divided into horizontal layers as indicated in Figure 4.89. The standardized pipe inlays (elbow, straight pipe and T-piece) are denoted , and respectively. The plane-leaving vertical streams are marked with x or o and empty positions not occupied by pipe inlays with O. The fixed pitch dimensions divide the plane into a square grid where every square represents a single cubic element which can be equipped with a number of pipe inlays. 

Pipes containing phosgene should be plainly labelled in accordance with the appropriate National Standards. Shut-off valves should be conspicuously labelled, and containers which are in use should be suitably marked. 

Applicable Standards. Pipe and tubing material is principally covered by ASTM or API standards. Problems may occur when ASTM A53 grade F pipe is specified and received by the site. It is generic pipe, suitable for benign services or handrails. Unfortunately, it may become intermixed with more critical service pipe because grade F, like other grades of A53, it is not identified with surface markings for product below 2 inches in diameter. 

An alternate pressure relief valve, with a marked set pressure not to exceed 150 o of the DOT service pressure, may be used in lieu of the rupture disk device if the flow capacity required for relief devices on TC/DOT Specification 4L insulated cylinders is provided at 120 70 of marked set pressure. See CGA S-1.1, Pressure Relief Device Standards—Part 1—Cylinders for Compressed Gases. [4] Installation must provide for (1) prevention of moisture accumulation at the seat by drainage away from that area, (2) periodic drainage of the vent piping, and (3) avoidance of foreign material in the vent piping. 

Easy identification Plastic piping is marked to aid in identification. Manufacturers mark and test their pipes and fittings according to ASTM Standards. This procedure makes it simple for users to properly identify the many types of plastic pipes and fittings that are available. 

Excavations following the accident uncovered, at a depth of about 3 feet, a 4-inch steel main. Welded to the top of the main was a steel tapping tee manufactured by Continental Industries, Inc. (Continental). Connected to the steel tee was a 1/2-inch plastic service pipe, (see Figure 13.2.) Markings on the plastic pipe indicated that it was a medium-density polyethylene material manufactured on June 11, 1970, in accordance with American Society for Testing and Materials (ASTM) standard D2513. The pipe had been marketed by Century Utility Products, Inc. (Century). The plastic pipe was found cracked at the end of the tee s internal stiffener and beyond the coupling nut. 

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