1-20 - Lecture 21 Pipe Specifications & Trickle Lateral...

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Lecture 21 Pip Plastic Pipe Specifications Trickle and sprinkle irrigation systems are It is important to understand how the technical Standards for the design and operation of pipelines are available from various professional organizations such as ASAE (American Society of Agricultural Engineers) and AWWA (American Water Works Association) Some of the material below is taken from ASAE standard S376.1 OCT92 ASAE standard S435 pertains to the use of PE pipe for microirrigation laterals Plastic pipe is now commonly used in irrigation and other pipelines ome of PVC (polyvinyl chloride), ABS VC pip are usually black ABS pipes are often used for buried drains and drainage pipes All of these pipe materials are called “thermoplastic” because the material can be repeatedly softened by increasing the temperature, and hardened by a decrease in temperature The pressure rating of plastic pipe (especially PVC) decreases rapidly with increasing temperature of the pipe and or water For example, at about 43 ° C (109 ° F) the PVC pressure rating drops to one-half of the nominal value at 23 ° C (73 ° F), and almost the same amount for PE PE pipe temperature can easily reach 43 ° C on a sunny day Unlike most metal pipes, these plastic pipe materials are immune to almost all types of corrosion, whether chemical or electrochemical The resistance to corrosion is a significant benefit when chemigation is practiced in a pressurized irrigation system The dimension ratio (DR) of a plastic pipe is the ratio of average diameter (ID or OD) to wall thickness ased, while other PE pipe is ID-based I. commonly built with plastic pipe, of which there are various types and specifications specifications affect design decisions (pipe sizing) S the most common types are (acrylonitrile-butadiene-styrene), and PE (polyethylene) P es are usually white, while ABS and PE PVC, ABS and some PE are OD-b Sprinkle & Trickle Irrigation Lectures Page 231 Merkley & Allen
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Merkley & Allen Page 232 Sprinkle & Trickle Irrigation Lectures Plastic pipe is currently manufactured up to a maximum diameter of 54 There are several standard dimension ratios (SDR) for several values, each with its own pressure rating (at 23 ° C) stronger than others plastic pipe is manufactured with non-standard dimension ratios; in these cases the ratio is called “DR” rather than “SDR” pipe size (IPS), plastic irrigation pipe (PIP), and others These are different standards for indirectly specifying pipe dimension ratios and pressure ratings The relationship between SDR, hydrostatic design stress (S in psi), and pressure rating (PR in psi) for OD-based pipe is defined by ISO standard 161/1-1978 The pressure rating (PR), which is the maximum recommended operating pressure, is determined by the following equations: inches thickness diameter Different types of PVC, ABS and PE compounds exist, some of which are Some Some pipe sizes are correspond to iron 2S PR OD SDR 1 1 t == ⎛⎞ ⎜⎟ ⎝⎠
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1-20 - Lecture 21 Pipe Specifications & Trickle Lateral...

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