Draft INDIAN STANDARD IRRIGATION EQUIPMENT COLLAPSIBLE EMITTING PIPE ( DRIP TAPE ) SPECIFICATION

Transcription

1 Doc No. : FAD 17 (2225) C Draft INDIAN STANDARD IRRIGATION EQUIPMENT COLLAPSIBLE EMITTING PIPE ( DRIP TAPE ) SPECIFICATION Deleted: AND TEST METHODS 1. Scope This Indian Standard gives mechanical and functional requirements for collapsible emitting pipes (Drip Tape), and where applicable, their fittings, and provides methods for testing conformity with such requirements. It also specifies the data to be supplied by the manufacturer to permit correct information, installation and operation in the field. Note 1.It is applicable to collapsible emitting pipes ( Drip Tapes ) with or without pressure regulation and to fittings dedicated to the connection of it. 2. It is applicable to collapsible emitting pipe ( Drip Tapes ) having wall thicknesses less than described in clause of IS 13488:2008. However upper limit for the wall thickness for the scope of this standard shall be 0.60mm (24 mil). 3. It is not applicable to porous pipe (pipe that is porous along its entire length) or soaker hose or pipe having outlets without presence of emitter/emitting unit, 4. It does not cover the performance of collapsible emitting pipe (drip tapes) as regards clogging since it is not applicable. Deleted: or soaker hose 2. Normative references For the purpose, of this standard the following Indian standards are necessary and adjuncts to this standard. The following Indian Standards also contain provisions, which through reference in this text, constitute provision of this standard. At the time of publication, the editions indicated were valid. All standards are subject to revision and parties to agreements based on this standard are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below. IS NO Title 2530:1963 Methods of test for polyethylene moulding materials and polyethylene compounds : 2008 Irrigation Equipment Emitting Pipe Systems Specification : 1989 Polyethylene pipes for Irrigation Laterals : 1992 Assembled joints between fittings and polyethylene pressure pipes Test of resistance to pull out. Formatted: Indent: Left: 1", First line: 0.5" 1

2 3. Terminology For the purposes of this standard, the following terms and definitions apply. 3.1 Collapsible Emitting Pipe ( Drip Tape ) Emitting pipe whose structure causes its cross section (which is generally round or rounded when the pressure at the inlet of the emitting pipe is within the range of working pressures recommended by the manufacturer) to alter itself when the pressure is zero, generally because of a small wall thickness or because of the flexible nature of the material from which the emitting pipe is made. 3.2 Multiple outlet emitter Emitter in which the output flow is divided and directed to several distinctly different locations. 3.3 Multiple emitters Multiple outlet emitter in which every outlet is a secondary emitter with its own flow rate. NOTE : The pressure relationship (q = kp m ), and the flow rate of each outlet is not generally dependent on the flow rate of other emitters. 3.4 Emitter/Emitting Unit Exponent (m) Numerical value that defines the exponential relationship between the emission rate and inlet pressure of an emitting unit. NOTE : q = kp m : for an exponent (m) of 0, the emission rate does not vary with pressure; for an exponent of 1, the emission rate varies linearly with pressure. 3.5 Flow rate Emission rate of an emitter or an emitting unit Deleted: pipe 3.6 Regulated emitter/emitting pipe or Pressure compensating emitter/emitting pipe Emitter/emitting pipe which maintains a relatively constant flow rate at varying water pressures at the emitter / emitting pipe inlet within the limits specified by the manufacturer. 3.7 Unregulated emitter/emitting pipe or Non pressure compensating emitter/emitting pipe Emitter/emitting pipe whose flow rate varies with inlet water pressure. 3.8 Regular emitter/emitting pipe Emitter/emitting pipe whose flow rate is different from zero when the inlet pressure is different from zero. 2

3 3.9 Non leakage emitter/emitting pipe Emitter/emitting pipe whose flow is zero whenever the pressure at the inlet of the emitter/emitting pipe is lower than a nominal pressure value (other than zero) declared by the manufacturer Minimum working pressure Lowest working pressure at the inlet to an emitter/emitting pipe recommended by the manufacturer to ensure proper operation of the emitter/emitting pipe 3.11 Maximum working pressure Highest water pressure at the inlet to an emitter/emitting pipe recommended by the manufacturer to ensure proper operation of the emitter/emitting pipe 3.12 Non reusable emitting pipe Emitting pipe not intended for reinstallation Reusable emitting pipe Emitting pipe designed for removal from the field and reinstallation with proper handling from one season to another or under other circumstances 3.14 Emitting unit Section of an emitting pipe, including all its hydraulic devices formed or integrated in the pipe during production and all of the emitter inlets, repeated at intervals, from which water is discharged to one clearly distinguishable location Unit emitting pipe Length of emitting pipe containing one emitting unit 3.16 Clamping band/ring Ring like or band like device used for obtaining a watertight joint between an emitting pipe and a fitting Fitting Connecting device suitable for attachment to an emitting pipe with or without a clamping band 3.18 Inlet fitting Fitting having one end suitable for connection to a standard irrigation pipe or appliance and the other end or ends suitable for connection to collapsible emitting pipe 3.19 In line fitting Fitting having both ends suitable for connection to collapsible emitting pipe 3

4 3.20 Nominal diameter Conventional numerical designation used to refer to the size of an emitting pipe Nominal test pressure, Pn Reference pressure, to be used for test purposes, of 100 kpa at the inlet of an unregulated emitter/emitting unit, or any other pressure as designated in manufacturer s publications 3.22 Nominal emission rate, qn Unregulated (Non pressure compensating) emitting pipe The emission rate, expressed in liters per hour, of an emitting unit operating at the nominal test pressure and at a water temperature of 27 ± 3 o C, as specified by the manufacturer Regulated (pressure compensating) emitting pipe The emission rate, expressed in liters per hour, of an emitting unit operating in the range of regulation and at a water temperature of 27 ± 3 o C, as specified by the manufacturer Nominal flow rate for multiple outlet emitter, qn The emission rate of each outlet, as specified in and , accordingly 3.23 Range of working pressures All water pressures at the emitting unit inlet between and including the minimum working pressure, p min, and the maximum working pressure, p max, recommended by the manufacturer to ensure proper operation Range of regulation for regulated collapsible emitting pipe All water pressures at the emitting unit inlet in which each emitting unit is expected to discharge the nominal emission rate Spacing of an emitting units Distance between two successive emitting units along an emitting pipe 3.26 Wall thickness of collapsible emitting pipe (drip tape) Numerical designation expressing thickness of collapsible emitting pipe. Generally expressed in millimeter or in mil unit. Conversion factor for mil is, 1 mil = 1/1000 th part of an inch or 0.025mm 4. Classifications Collapsible emitting pipes are classified according to the following criteria (see 4.1 to 4.5) 4 Deleted: The Deleted: the Deleted: generally Deleted: is Formatted: Bullets and Numbering

5 4.1 Reusability (collapsible emitting pipes) Two categories of use are classified: Non reusable emitting pipes; Reusable emitting pipes. 4.2 Type of pressure regulation Two categories of operation are classified: Unregulated emitting pipes; Regulated emitting pipes. 4.3 Type of operation at low pressure Two categories of operation at low pressure are classified: Regular Non leakage 4.4 Type of multiple outlet emitter Multiple emitters Regular multiple outlet emitter. 5. Construction and materials 5.1 General The collapsible emitting pipe, its parts and fittings shall have no manufacturing defects that could impair performance. The construction of the collapsible emitting pipe and its fittings shall permit their easy connection, with or without clamping bands, whether the connection is made manually or by means of suitable tools supplied by the manufacturer. Deleted: emitter/ 5.2 Materials The material used in the manufacture of collapsible emitting pipes and their fittings shall be resistant to fertilizers and other chemicals commonly employed in agricultural irrigation and shall be suitable for use with water at temperatures up to 60 o C and at operating pressures designated by the manufacturer The materials shall, so far as possible, not support the growth of algae and bacteria. The parts that are exposed to light shall be opaque and protected against UV degradation Extrusion compound shall be manufactured from a mixture of the following 5

6 A. Polyethylene which may includes copolymer of ethylene and higher olefins, in which the higher olefin constituents does not exceed 10% (m/m) B. Anti oxidant in an amount not exceeding 0.5% (m/m) C. Carbon Black equivalent to a content of 2.5±0.5% (m/m) and complying with the following requirements I. Toluene extracts not more than 0.1% (m/m). Determination of toluene extract of carbon black shall comply with the test procedure given in IS Annexure A II. Maximum volatile matter 9.0% (m/m). Determination of maximum volatile matter in carbon black shall comply with test procedure given in IS , Annexure B. D. When tested in accordance with IS I. The percentage of carbon black in the material shall be 2.5 ± 0.5% by mass. II. The dispersion of carbon black shall be satisfactory Addition of not more than 10% of the manufacturers own rework material produced during the manufacture and works testing of collapsible emitting pipe complying with this standard is permitted. No other rework material shall be used. 5.3 Dimensions (collapsible emitting pipe) The manufacturer shall specify the nominal outside diameter, inside diameter and wall thickness of the collapsible emitting pipe, in millimeters or in mil, and the actual dimensions of the product shall comply with those declared by the manufacturer in accordance with and The dimensions of the connecting fittings shall fit the dimensions of the collapsible emitting pipe, to ensure easy and reliable connection. 5.4 Fittings (collapsible emitting pipe ) The manufacturer shall be able to supply, for each type and size of collapsible emitting pipe, fittings suitable in size and shape to make secure connections to the collapsible emitting pipe. The jointing, made with or without the use of clamping bands, shall be of sufficient strength to withstand the full range of working pressures. Clamping components, such as bands and screws, shall be of non corroding materials or of materials protected against corrosion. 6

7 6. Test specimens and conditions 6.1 Test specimens The sample shall include 25 specimens taken at random from each production lot. A specimen is composed of either one emitter or one non truncated emitting unit from the emitting pipe. The number of test specimens (emitters/emitting units) required for each test is indicated in clause 7 for the relevant tests. Ensure that the test specimen is not taken from adjacent sections of the emitting pipe and does not contain either the first or last emitting unit of the lot. For multiple outlet emitters, the sample shall include at least 10 emitters or 25 outlets. Deleted: For emitting pipes, e 6.2 Order of tests The tests shall be conducted in the order given in Clause 7. All tests, beginning with that of 7.2 shall be conducted on specimens tested according to Test conditions Unless otherwise specified, carry out all tests at ambient air temperature and at a water temperature of 27 C ± 3 C. Ensure that the water used is clear water filtered through a filter with nominal aperture of 75 µm, or as recommended by the manufacturer. 6.4 Accuracy of measuring devices The water pressure shall be measured with measuring devices capable of measuring with an error not exceeding 2% of the actual values During the test, the pressure shall not vary by more than 2%. The flow rate shall be measured with measuring devices capable of measuring with an error not exceeding ± 2% of the actual flow rate. 7. Test methods and requirements Formatted: Bullets and Numbering 7.1 Uniformity of flow rate General This test applies to regulated and unregulated emitters/emitting pipes. The test sample shall include 25 emitters/emitting units in accordance with the requirement in 6.1. When multiple emitters are tested, each outlet shall be considered as a single emitter Unregulated emitters/emitting pipes Measure the flow rates of the emitters/emitting units when the water pressure at the inlets of the emitters/emitting units equals the nominal test pressure. Record separately the measured flow rate of each emitter / emitting unit. Calculate the coefficient of variation, Cv, from the following formula: 7

8 C v = X 100 where: is the standard deviation of the flow rates for the sample, in liters per hour; is the mean flow rate of the sample, in liters per hour. Note: For the purpose of measuring emission rate, collect a water sample from each emitting unit for 3 minute and calculate the emission rate for each outlet The mean emission rate of the test sample shall not deviate from the nominal emission rate,(qn) by more than 5 percent for category A, or not more than 10 percent for category B. Table 1 Uniformity Values (According to 7.1.2) Category Deviation of q from q n, Max Coefficient of Variation C v (1) (2) (3) A 5% 5% B 10% 10% The coefficient of variation (Cv) of the emission rate of the test sample shall not exceed 5 percent for category A, or 10 percent for category B Regulated emitters/emitting pipes Condition the emitters / emitting units in the test sample by operating them for a total of 1 h. The conditioning procedure shall consist of the following steps. a) Set the minimum working pressure and maintain it for 3 min. b) Set the maximum working pressure and maintain it for 3 min. c) Set the minimum working pressure and maintain it for 3 min. d) Set the maximum working pressure and maintain it for 3 min. e) Set the minimum working pressure and maintain it for 3 min.

9 f) Set the maximum working pressure and maintain it for 3 min. g) Set the pressure at the midpoint of the range of regulation and maintain it until the total time of the conditioning procedure (1 h) is completed. h) Immediately after conditioning and while maintaining the inlet pressure at the midpoint of the range of regulation, test the emitters/emitting units according to The emitters/emitting units shall comply with the requirements of Flow rate as a function of inlet pressure Perform the tests for determining flow rate as a function of inlet pressure as a continuation of the tests performed in accordance with 7.1. When multiple emitters are tested, each outlet shall be considered as a single emitter Test method Emission Rate of Emitting Unit as a Function of Inlet Pressure Number the emitting units tested according to 7.1, in ascending order according to the measured emission rate. (No. 1 shall be given to the emitting unit of lowest emission rate and No. 25 to the emitting units of highest emission rate) Select 4 emitting units from the series obtained, Nos. 3,12,13,23 and measure their change in emission rate as a function of the inlet pressure. Test each emitting unit in steps not greater than 50 kpa, from zero pressure up to 1.2 P max. Regulated emitting units shall be tested at three or more different pressure within the range of regulation, at rising and falling inlet pressure. The reading of the results shall be taken at least three minutes after arriving at the test pressure. If the inlet pressure exceeds the desired pressure by more than 10 kpa during its rise and fall, return to p min and repeat the test. Test non leakage emitters/emitting pipes in steps not greater than 10 kpa from zero pressure up to 0.5 Pmax, starting from 0.5 Pmax, continue raising the pressure in steps not exceeding 50 kpa up to 1.2 P max Unregulated Emitting Pipe Calculate for each pressure value, the average emission rate, q, obtained by measuring the emission rate of the four emitting units at rising pressure. Plot the curve, q as function of inlet pressure The curve of q as a function of inlet pressure shall conform to the curve presented in the publication of the manufacturer within an allowable 9

10 deviation of not more than + 5 percent for category A and + 10 percent for category B For non leakage emitters/emitting units, the pressure at which flow begins and the pressure at which the flow stops shall not vary by more than 10% from the manufacturer s declared pressure Regulated Emitting Pipes Calculate, for each inlet pressure value, p i, the average emission rate q obtained by measuring the emission rate of the four emitting units at rising and falling pressure (the average of 8 emission rate measurement) Plot the curve, q as function of inlet pressure The value of q shall not deviate from the nominal emission rate by more than 5 percent for category A or not more than 10 percent for Category B For non leakage emitters/emitting units, the pressure at which flow begins and the pressure at which the flow stops shall not vary by more than 10% from the manufacturer s declared pressure. 7.3 Determination of emitter/emitting unit exponent The relation between the flow rate, q, in liters per hour, and the inlet pressure in an emitter/emitting unit, p, in kilopascals, is given by the formula: q k x p m where, k m is a constant; is the emitting exponent. Using all the q and p values obtained in or 7.2.3, calculate the exponent, m, from the following formula: Σ( log p ) (log q ) 1/n ( Σ log p ) ( log i i i ) i m= Σ (log p i ) 2 1/n (Σlog p i ) 2 where, i is 1,2,3 n; n is the number of pressure values used in or 7.2.3; is the mean flow rate, in liters per hour; p is the inlet pressure, in kilopascals. 10

11 For regulated emitters/emitting pipes, the value of the emitting exponent, m, shall not exceed 0.2. The calculated exponent shall not deviate from the manufacturer s declaration by more than ± 5% NOTE : The emitter / emitting unit constant, k, can also be calculated by the following formula: Where, i is 1,2,3 n; n is the number of pressure values used in or 7.2.3; qi is the mean flow rate, in litres per hour; pi is the inlet pressure, in kilopascals; m is the emitter/emitting unit. 7.4 Dimensions Wall thickness of emitting pipe Measure the wall thickness using a measuring instrument having an accuracy of 0.01 mm. The measurement may be rounded to the nearest 0.02 mm. Measure the wall thickness of the emitting pipe at four points equally spaced, on the periphery of the pipe. Repeat the test at two cross sections. In the event of a part of the pipe of the pipe wall being thicker by design (for example, a flap in the emitting pipe), disregard such increased thickness. The wall thickness of the emitting pipe, when measured individually at each of the four points, shall not be less than ±10% of the declared wall thickness. Wall thickness shall be expressed in millimeters. Alternatively, it can also be expressed in mil using conversion factor as mentioned in Inside diameter of emitting pipe Measure the inside diameter using a measuring instrument having an accuracy of 0.05mm. The measurement may be rounded to the nearest 0.1 mm. For measuring the Inside diameter of emitting pipe, insert in to the end of the pipe a specific Go No Go guage, first enter Go side of the guage, it should go inside the tube without much force but at the same time it should not remain loose in the tube. For example A Go No Go guage sketch is given below for 16 mm inside diameter tube. Deleted: P 11

12 Fig.1 Inside diameter measurement tool, GO NO GO gauge Alternative measuring methods to measure the inside diameter of the emitting pipe, insert a conical part (apex angle not greater than 10 ) into the end of the emitting pipe, taking care not to enlarge the pipe diameter. Mark on the cone the circle made by the end of the pipe and measure its diameter. Fig.2 Inside diameter measurement tool, conical gauge Alternatively, Calculation of the diameter by measuring the pipe circumference may be used. The measured inside diameter shall not deviate by more than + 0.2, 0.0 mm from the declared diameter Spacing of emitting units Measure three spacing of emitting units accurately to the nearest 1.0 mm. The spacing of the emitting units shall not deviate by more than 5% from the spacing declared by the manufacturer. 7.5 Resistance to hydraulic pressure Resistance to hydraulic pressure at ambient temperature, 27 ± 3 C Carry out the test on a length of emitting pipe consisting of five emitters or five emitting units joined by means of in line fittings. Carry out the test in two stages (see and ) Connect the assembly to a source of water (connecting the emitting pipe by means of an inlet fitting) and close its outlet end. Fill the assembly with water and check that no air remains trapped in the pipe. Increase the water pressure gradually (10 s minimum) to 1.2 Pmax for non reusable emitting 12

13 pipes or to 1.8 Pmax for reusable emitting pipes and for emitters, and maintain the test pressure for 1 h The assembly shall withstand the test pressure without showing signs of damage to the emitters/emitting pipes, the emitting units or the connecting fittings. The assembly shall not pull apart, and no leakage shall occur at the inlet fitting. Leakages not exceeding the emission rate of one emitting unit are permissible at inline fittings Reduce the test pressure to the nominal test pressure and maintain it for at least 3 min. Measure the flow rate of each emitter/emitting unit. For emitters designed to enter a flush mode at high pressures to remove clogs, reduce the pressure to zero before measuring flow rate at the nominal pressure. The flow rate of each emitter/emitting unit shall not deviate by more than ± 10% from its original flow rate as measured in Resistance to hydraulic pressure at elevated temperature Carry out the test on an assembly consisting of three emitters connected to a lateral or of three unit emitting pipes joined by means of in line fittings Connect the assembly to a source of water by means of an inlet fitting and close its outlet end. Fill the assembly with water and check that no air remains trapped in the pipe. Raise the water pressure gradually (10 s minimum) to the maximum working pressure and maintain the pressure for 1 h while the emitting pipe test assembly is immersed in water at 60 C ± 2 C. The assembly shall withstand the test pressure without showing signs of damage Remove the test assembly from the water and leave it for 30 min at ambient temperature. Apply a hydrostatic pressure, Pn, for at least 3 min at 27 C ± 3 C and measure the flow rate of each emitting unit. The flow rate of each emitter/emitting unit shall not deviate by more than ± 10% from its original flow rate, as measured in Burst pressure test 13 Carry out the test on collapsible emitting pipe having free length between the two end fittings equals to ten times the inside diameter but not less than 250mm.

14 Carry out the test not earlier than 24 hrs. after the tube is manufactured Connect the tube ends with locking plugs at both ends in such a way that the axial forces coming from the internal pressure are transmitted to the tube Connect the assembly to a source of water by means of an inlet fitting and close its outlet end. Fill the assembly with water and check that no air remains trapped in the pipe. Raise the water pressure gradually (10 s minimum) till the tube bursts while the emitting pipe test assembly is immersed in water at 20 C ± 2 C. The bursting pressure shall not be less than four times nominal test pressure, Pn 7.6 Resistance to tension (emitting pipe) Carry out the test at a temperature of 27 C ± 3 C. If the emitting pipe is reusable, mark lines, 150 mm apart, on the unit emitting pipe. Fasten each unit emitting pipe in the grips of a tension testing machine and uniformly increase (over 20 s to 30 s) the pull on the unit emitting pipe to a) 160 N for non reusable emitting pipes (see clause 4.1.1), or b) 180 N for reusable emitting pipes (see 4.1.2). Notwithstanding this, if the manufacturer s publications (see Clause 10) declare that the maximum permitted tension force is less than the abovementioned force; perform the test as specified here with the tension force declared by the manufacturer. Maintain the tension force for 15 min, then release. Non reusable emitting pipes shall withstand the test tension force without breaking or tearing. Reusable emitting pipes shall withstand the test tension force without breaking or tearing, the nominal flow rate in the test specimen shall not vary by more than ± 10% from the flow rate measured before testing, and the distance between the two marked lines shall not vary by more than ± 5% from the distance measured according to this sub clause. 7.7 Resistance to tensile stress The test sample shall be a length of collapsible emitting hose of at least 100 cm sampled in accordance with the requirements of clause Generate an axial force vs. elongation curve using a suitable tensile test machine with a loading rate of 9 N/min. One acceptable method is described below. Deleted: l 14

15 Fig.3 Tensile test apparatus Attach a tension indicating device such as a load cell or an analog scale to a fixed support in a vertical configuration as shown in Fig. 3. Attach one end of the sample to be tension indicating device as shown. Measure and record the length of the unstressed sample Apply a tensile load, f, of approximately 20 N and maintain the force for 2 minutes. The tensile load can be applied by attaching weights to the end of the sample Without removing the load, measure and record the resulting elongation, δ, of the sample as a percentage of its original length. Formatted: List Paragraph, Centered, Indent: Left: -0.06", Hanging: 0.06", Space After: 10 pt, Line spacing: Multiple 1.15 li, Tabs: Not at 1.75" Repeat clause and each time increasing the tensile load, f, by an increment no greater than 20 N until the sample is ruptured or elongated more than 25%. 15 Fig 4 Example load elongation curves

16 Plot the curve of applied load, f, versus elongation & sample loadelongation curves are shown in Fig Measure and record the yield strength, Ty, if the sample as the applied load at the point where the load elongation curve markedly changes slope as shown in Fig. 4, curve A if there is no distinct change in slope as shown in Fig. 4, Curve B, calculate the 0.1% offset strength as described in Annexure A. 7.8 Resistance to pull out of joints between fittings and polyethylene reusable emitting pipes. This test shall be performed in accordance with IS 13479, but the test pull out load shall be according to 7.6, applied for 15 min or alternatively dead weight may be used for applying the test pull. Notwithstanding the above, if the manufacturer s publications (see clause 10) declare that the maximum permitted tension force is less than the abovementioned force, perform the test as specified here with the tension force declared by the manufacturer. The fitting shall not pull out from the emitting pipe. Where the emitting pipe is not made of polyethylene or the pipe wall is not uniform, this test may be performed in conjunction with the resistance to tension test in 7.6 by connecting between two sections of emitting pipe, each at least 300 mm long. 7.9 Resistance of Collapsible Emitting Pipe to Environmental Stress Cracking Formatted: Indent: Left: 1", First line: 0" Formatted: Indent: Left: 0", Hanging: 0.5" Acceptance Test The test procedure shall conform to the procedure described in Annex D of IS 12786:1989 (Amendment no.5), except for the following: Condition the test specimen in an air circulating oven at 80 ± 1 0 C for 1 hour. Then air cool and U bend the specimen and immerse in a constant temperature bath, containing the reagent. % Concentration of Surface active agent = 10% Test temperature = 77 ±3 C Test duration = 1 hour Type Test The test procedure shall confirm to the procedure described in Annex D of IS : 1989 (Amendment no.5), except for the test temperature and test duration which shall be as specified below: % Concentration of Surface active agent = 10% Test temperature = 77±3 C Test duration = 48 hours 16

17 7.10 Water tightness of the collapsible emitting pipe assembly Connect five emitting units by the connection methods recommended by the manufacturer (see clause 10) Connect one end of the collapsible emitter pipe assembly to a source of hydraulic pressure and plug the other end of the assembly Perform the test on five emitters connected to a lateral at a temperature of 27 C ± 3 C. Increase the pressure in three steps: Deleted: er Deleted: ers Deleted: to the pipe a) 5 min at 0.4 Pmax, b) 5 min at 0.8 Pmax, c) 60 min at 1.2 Pmax, No leakage shall occur through the connections to the emitting pipe, except at points of emitter discharge. Deleted: emitter bodies or their 8. Designation 8.1 Non Regulated collapsible emitting pipe: These emitting pipes shall be designated by, a) the words collapsible emitting pipe, b) reference to this Indian Standard, c) nominal diameter in millimeters, d) nominal emission rate in litres per hour, e) thickness of collapsible emitting pipe in millimeters or in mil, and uniformity category. Example: Collapsible emitting pipe IS xxxxx A designates a collapsible emitting pipe complying with this Indian Standard, of 16 mm nominal diameter, 2 litres/h emission rate, with thickness of collapsible emitting pipe 0.2 mm, non regulated and confirming to uniformity category A. <#> Page Break 8.2 Regulated Collapsible Emitting Pipe: These collapsible emitting pipes shall be designated by, a) the words collapsible emitting pipe, b) the reference to this Indian Standard, c) nominal diameter in millimeters, d) nominal emission rate in litres per hour, e) thickness of collapsible emitting pipe in millimeters or in mil, f) symbol "PC" to indicate use of regulated emitters, and 17

18 g) uniformity category. Example: Collapsible emitting pipe IS xxxxx PC A designates a collapsible emitting pipe complying with this Indian Standard, of 16 mm nominal diameter, 2 litres/h emission rate, with thickness of collapsible emitting pipe 0.2 mm, regulated (pressure compensated) and confirming to uniformity category A. 9. Marking and packing Formatted: Bullets and Numbering 9.1 Each reusable collapsible emitting pipe shall bear clear markings of any suitable colour. Alternately laser marking/etching may also be permitted. Following particulars shall be indicated on the collapsible emitting pipe: a) Name of manufacturer or his registered trade mark ; b) Year of manufacture; c) Batch or Code No.; d) Designation in accordance with 8 e) Arrow indicating direction of flow (only if flow direction affects operation of collapsible emitting pipe); and f) Spacing of emitting units, in centimeters The marking on non reusable collapsible emitting pipes (clause 4.1.1) does not have to be permanent but shall appear on the package in accordance with the marking requirements of BIS Standard Marking The product may also be marked with the standard mark The use of standard mark is governed by the provision of the Bureau of Indian Standards Act and the Rules and Regulations made there under. The details of conditions under which the license for the use of Standard Mark may be obtained from Bureau of Indian Standards. 9.3 Packing of collapsible emitting pipe When the collapsible emitting pipes are supplied in coils, each coil shall carry an attached tag bearing the following information in clear, legible and permanent writing: a) Name and address of manufacturer; b) Designation and Catalogue number of emitting pipe c) Nominal diameter of collapsible emitting pipe d) Thickness of collapsible emitting pipe. e) Length of collapsible emitting pipe in coil f) Year of production and manufacturing lot g) Classification according to 4.1, 4.2 and

19 h) Nominal emission rate of unit emitter/emitting unit and nominal working pressure for unregulated emitting pipe or working pressure range for regulated emitting pipe; i) Spacing of emitting units 10. Data to be supplied by the manufacturer The manufacturer shall make available to the user together with the collapsible emitting pipe and fittings, catalogues or information sheets that include the following data: a) Catalogue number of collapsible emitting pipe and fittings; b) Type of fittings for connecting emitting pipe to supply network or appliances; c) Instruction sheet for proper operation of collapsible emitting pipe (the instruction sheets shall be dated); d) The words Uniformity category A or Uniformity category B as applicable, including the relevant values given in Table 1; e) Classification of collapsible emitting pipe (clause 4); f) Emitter unit exponent as detailed in 7.3 g) Details of suitable fittings (including code number as marked on the fitting) for different applications; h) Installation instructions for the collapsible emitting pipe and fittings; i) Nominal emission rate of emitter/emitting unit; j) Inside diameter of collapsible emitting pipe; k) Wall thickness of collapsible emitting pipe; l) Range of working pressure of the collapsible emitting pipe; m) Operating characteristics of collapsible emitting pipe (7.2); n) Limitations of collapsible emitting pipe use (fertilizers, chemicals, etc); o) Range of regulation (if any) p) Maximum permitted tension force [if the maximum permitted tension force, according to the manufacturer s discretion is < 160 N for non reusable emitting pipes (Class 4.1.1) or < 180 N for reusable emitting pipes (Class 4.1.2)]; q) Filtration requirements; r) Spacing of emitting unit in collapsible emitting pipe; s) Minimum recommended radius for coiling collapsible emitting pipe; t) Maintenance and storage requirements; u) Nominal test pressure; v) The length of the emitting pipes in each reel. w) Measured yield strength. Deleted: pipe Formatted: Bullets and Numbering Deleted: whenever asked for Deleted: unit Deleted: pipe 19

20 Annexure A ( clause 7.7.3) Determination of Offset yield strength Formatted: Font: 12 pt, Not Bold, Italic, Complex Script Font: 12 pt, Bold, Italic A. Offset yield strength the stress at which the strain exceeds by a specified amount (the offset) an extension of the initial proportional portion of the stress strain curve. It is expressed in force per unit area, usually megapascals. 1. This measurement is useful for materials whose stress strain curve in the yield range is of gradual curvature. The offset yield strength can be derived from a stress strain curve as follows, 2. On the strain axis lay off OM equal to the specified offset. 3. Draw OA tangent to the initial straight line portion of the stress strain curve. 4. Through M draw a line MN parallel to OA and locate the intersection of MN with the stress strain curve. Strain Fig.5 Offset yield strength The stress at the point of intersection r is the offset yield strength. The specified value of the offset must be stated as a percent of the original gage length in conjunction with the strength value. Example: 0.1% offset yield strength = MPa, or yield strength at 0.1 % offset = MPa. 20