INTERNATIONAL ASSOCIATION OF PLUMBING AND MECHANICAL OFFICIALS MATERIAL AND PROPERTY STANDARD FOR

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1 INTERNATIONAL ASSOCIATION OF PLUMBING AND MECHANICAL OFFICIALS MATERIAL AND PROPERTY STANDARD FOR PUMP/DOSE, SUMPS AND SEWAGE EJECTOR TANKS WITH OR WITHOUT A PUMP IAPMO PS PURPOSE 1.1 The purpose of this standard is to provide information on pump/dose, sumps and sewage ejector tanks with or without a pump. It shall serve as a guide for producers, distributors, architects, engineers, contractors, installers, inspectors and users; and to promote a better understanding regarding materials, manufacture, and installation. 1.2 The provisions of this standard are not intended to prevent the use of any alternate material or method of construction, provided any such alternate meets the intent of this Standard. 2. SCOPE 2.1 Pump/dose, sumps and sewage ejector tanks with or without a pump shall be used when gravity drainage is impossible or impractical. The design of the tank shall be of sufficient volume to allow for the proper operation of the pump and the switch assembly. 3. BASIC REQUIREMENTS 3.1 Device shall be of such a design to collect sewage and waste water for the purpose of ejecting this material to public or private sewers. 3.2 Device shall be provided with substantial covers having a resealable manhole or equivalent to permit access for inspection, repairs and cleaning. Penetration to the tank and or access opening shall be properly sealed. 3.3 Inlet, outlet and vent pipe sizes shall be as specified in Chapters 7 and 9 of the Uniform Plumbing Code as published by the International Association of Plumbing and Mechanical Officials. 1 of 13

2 3.4 Written installation instructions shall be provided with the product to allow for proper assembly, which addresses the maximum recommended depth of earth cover for underground installation. When installing in a hazardous location, equipment including pump(s), controls, piping disconnects, etc., installation shall be in accordance with NFPA Means of Access. The holding tank and the pump shall be accessible for inspection, cleaning and repair via a cover opening. Pump shall be removable for servicing and repair. 3.6 Pumps. When pump is supplied with tank, the pump shall comply with the applicable UL Standard Grinder pump devices including, controls, piping disconnects, tank, etc., shall comply with Appendix C in this standard or Section 9 of NSF/ANSI Pump/Dose Tanks. Tanks shall comply with Section 5.3 of this standard and shall be sized in such a way as to discharge a predetermined amount of effluent through the use of a siphon or sewage effluent pump. Tanks with a siphon shall comply with the requirements in Section and of CSA B Tanks shall be vented to allow air to enter the tank during pumping. Venting can be accomplished either through an access opening or piping. No openings, drains, or access ways shall be below the level of the invert of the inlet on a pumping/dosing tank. Tanks shall be able to accommodate an alarm system that warns when the pump or siphon fails or malfunctions. Appropriate tank tie downs or buoyancy collars should be employed for pumping/dosing tanks based on known permanent or periodic high ground water conditions as determined by the system designer. Note: A pumping/dosing tank is a chamber designed to receive sewage effluent from a septic tank. The pump/dose tank can be an integral part of the septic tank (separated by a partition) or an independent unit separate from the septic tank. In either case, the volume contained within the pump/dose tank does not form part of the working capacity of the septic tank. 4.1 Concrete 4. MATERIALS All concrete tanks shall be coated on the interior with an approved waterproof 2 of 13

3 bituminous compound complying with ASTM D 41, Asphalt Primer Used in Damproofing and Waterproofing and ASTM D 449, Type A, Asphalt Used in Damproofing and Waterproofing or ASTM D 2823, Type I for Asphalt Roof Coatings and shall be applied per the manufacturer s recommendation Concrete shall have a minimum compressive strength of twenty-five hundred (2500) pounds per square inch. Concrete shall have a maximum water/cementing materials ratio of 6 gal./sack of cement and shall comply with the following ASTM designations: ASTM C 150, Specification for Portland Cement; ASTM C 260, Specification for Air Entraining Admixtures for Concrete; ASTM C 33, Specifications for Concrete Aggregates; ASTM C 94, Specification for Ready Mix Concrete and ASTM C 618, Specification for Fly Ash and Raw or Calcined Natural Pozzolan for use as a mineral Admixture in Portland Cement Concrete Walls shall have a thickness of at least three (3) inches, except where engineering analysis and production methods can justify a lesser thickness The minimum area of steel reinforcement (in both directions) of the structural elements shall be times the gross cross-sectional area of the reinforced section if of bars; and not less than three-fourths (3/4) as much if of welded wire fabric. All reinforcement shall be protected with a minimum of one (1) inch of concrete and shall comply with ASTM A 185, Specification for Steel Welded Wire Fabric, Plain for Concrete Reinforcement and ASTM A 615, Specification for Deformed and Plain Billet-Steel Bars for Concrete Reinforcement. Tanks shall be of sufficient strength to resist stresses caused during handling and installation without structural cracking If repairs are necessary they shall be carried out in accordance with the appropriate provision of ASTM Standards (refer to Section and 4.1.4). 4.2 Glass-Fiber-Reinforced Polyester Terminology - Unless otherwise indicated, the plastics terminology used in this Standard is in accordance with the definitions given in ASTM D 883, Definitions of Terms Relating to Plastics Materials - The tank, cover, flanges, etc., shall be made from polyester resins with glass-fiber reinforcement Resin - The resin shall be a chemical-resistant grade of polyester resin and shall be evaluated as a laminate by test (see Appendix A for a recommended test), or known from previous service to be acceptable for the environment. The same resin shall be used throughout the laminate. Other plastic resins proven to be as satisfactory for the Copyright 2006 by International Association of Plumbing and Mechanical Officials. All rights reserved. Printed in the United States of America. No part of 3 of 13

4 intended end use will be acceptable. A typical isophtalic polyester which will meet these requirements is described in Appendix B Reinforcing Material - The reinforcing material shall be of a suitable commercial grade (1) PRIMARY CHEMICAL RESISTANT SURFACE (2) INTERNAL ANTI-WICKING BARRIER TO DESIRED THICKNESS FOR STRENGTH (3) ADDITIONAL STRUCTURAL REINFORCING SECTION (4) EXTERNAL ANTI-WICKING BARRIER (5) EXTERIOR SURFACE of glass fiber (E glass) treated with coupling agent, approved by the glass fiber manufacturer, that will provide a compatible bond between the resin and the glass. Glass-fiber surfacing materials, if used, shall be of a chemical-resistant glass (C glass) bonded with a suitable binder Fillers and Pigments - The resins used shall not contain fillers except as required for viscosity control. Up to two (2) percent by weight of the total resin content of thixotropic agent that will not interfere with visual inspection may be added to the resin for viscosity control. Resins may contain pigments and dyes by agreement between fabricator and purchaser, recognizing that such additions may interfere with visual inspection of laminate quality Laminate The laminate shall consist of the following: (1) Primary chemical-resistant surface. (2) Internal anti-wicking barrier. (3) Additional structural reinforcing section if required to meet the properties shown in Table 1. (4) External anti-wicking barrier. (5) Exterior Surface. NOTE: The compositions specified in 4.1 (1), (2), (4), and (5) are intended to achieve optimum chemical resistance. 4 of 13

5 4.2.7 Primary Chemical Resistant Surface - This surface shall be between and inch (0.1 and 0.3 mm) thick. It shall be a reinforced resin rich surface. 1 It shall be free from cracks and crazing and shall have a smooth finish. Some waviness is permissible. It shall be made in such a manner that air has not been allowed to inhibit the cure of the surface exposed to the environment Internal Anti-Wicking Barrier - Not less than inch (2.5 mm) of chemical-resistant Thickness (in.) (mm) PROPERTY AT 3/8 and Test 73.4 o F (23 o C) 3/16(4.8) 1/4(6.4) 5/16(7.9) Up (9.5) Method psi(mpa) psi(mpa) psi(mpa) psi(mpa) Ultimate tensile strength, min. 9,000(62) 12,000(83) 13,500(93) 15,000(103) Par Flexural Strength, min. 16,000(110) 19,000(131) 20,000(137) 22,000(152) Par Flexural modulus of elasticity (tangent) 700, , ,000 1,000,000 Par min. (4823) (5512) (6201) (6895) laminate next to the inner surface shall be reinforced with not less than 20 percent nor more than 30 percent by weight of mat or chopped strand Additional Structural Reinforcing Section - This layer or body of the laminate shall be of chemically resistant construction suitable for the intended use and providing the additional strength necessary to meet the tensile and flexural requirements. Where separate layers such as mat, cloth or woven roving are used, all layers shall be lapped at least one (1) inch (25 mm). Laps shall be staggered when woven roving or cloth is used; layers of chopped strand glass shall be placed as alternate layers External Anti-Wicking Barrier - Same as Exterior Surface - This surface shall consist of a chopped strand glass over which shall be applied a resin-rich coating as described in paragraph Tanks intended for above ground exterior use, it shall be coated to protect against UV rays Cut Edges - All cut edges shall be coated with resin so that no glass fibers are exposed and all voids are filled. Structural elements having edges exposed to the chemical environment shall be made with chopped strand glass reinforcement only Wall Thickness - The minimum wall thickness shall be as recommended by the manufacturer but in no case shall it be less than 3/16 inch (4.8 mm) regardless of operating conditions Mechanical Properties - In order to establish proper wall thickness and other design Copyright 2006 by International Association of Plumbing and Mechanical Officials. All rights reserved. Printed in the United States of America. No part of 5 of 13

6 characteristics, the minimum physical properties for any laminate shall be as shown in Tank Wall Thickness-- 3/16 1/4 5/16 3/8 7/16 1/2 9/16 5/8 11/16 3/4 in. (mm) (4.8) (6.4) (7.9) (9.5) (11.1) (12.7) (14.3) (15.9) (17.5) (19.1) Min. outside overlay width, in. (mm) (100) (100) (125) (150) (175) (200) (225) (250) (275) (300) Min. inside overlay width, in. (mm) (100) (100) (125) (125) (150) (150) (150) (150) (150) (150) Table 1 and paragraph Table 1 Requirements for Properties of Newly Fabricated Reinforced Polyester Laminates Surface Hardness - The laminate shall have a Barcol Hardness of at least the manufacturer s minimum specified hardness for the cured resins when tested in accordance with ASTM D2583. This requirement applies to both interior and exterior surfaces Appearance - The finished laminate shall be as free as commercially practicable from visual defects such as foreign inclusions, dry spots, air bubbles, pinholes, pimples and delamination. Both surfaces shall be free from cracks and crazing and have a smooth finish and an average of not more than 2 pits per square foot, (21 pits/m 2 ) providing the pits are less than 1/8 inch (3.2 mm) diameter and not more than 1/32 inch (0.8 mm) deep and are covered with sufficient resin to avoid exposure of inner surface fabric. Some waviness is permissible provided the surface is smooth and free from pits. Unless otherwise specified, ASTM D2563 visual acceptance level 3 shall be the minimum standard for acceptance Shell Joints - Tanks manufactured in sections may be joined by use of flanges, bell and spigots and butt joints. All joints shall meet the corrosion resistance requirements for the intended end use Flange, bell and spigot joints shall be designed and bonded in accordance with accepted engineering practices Butt joints shall consist of glass fiber reinforced resin at least the thickness of the heaviest section being joined. The reinforcement shall be applied both inside and out. Table 2 6 of 13

7 Minimum Total Widths of Overlays for Reinforced-Polyester Tank Shell Joints Testing and Test Methods Specimens - Tests shall be made on specimens cut from waste areas when possible; otherwise, the specimens shall be cut from flat laminates prepared in the same construction and by the same techniques as the process equipment. In all cases, the average value of the indicated number of specimens shall be used to determine conformance with the detailed requirements Conditioning - The test specimens shall be conditioned in accordance with Procedure A of ASTM Designation D618, Standard Methods of Conditioning Plastics and Electrical Insulating Materials for Testing Tests Glass Content - The glass content shall be determined in accordance with ASTM Designation D 2584, Tentative Method of Test for Ignition Loss of Cured Reinforced Resins, except that the specimens tested shall be approximately one (1) square inch in area and low temperature pre-ignition prior to placement in muffle furnace is recommended. The average for five specimens shall be considered to be the glass content Tensile Strength - Tensile strength shall be determined in accordance with ASTM Designation D 638, Test for Tensile Properties of Plastics (Tentative) except that the specimens shall be the actual thickness of the fabricated article and the width of the reduced section shall be one inch. Other dimensions of specimens shall be as designated by the ASTM standard for Type 1 specimens for materials over 1/2 inch to inch inclusive. Specimens shall not be machined on the surface. Tensile strength shall be the average of five specimens tested at in./min. speed Flexural Strength - Flexural strength shall be determined in accordance with Procedure A and Table 1 of ASTM Designation D 790, Standard Method of Test for Flexural Properties of Plastics, except that the specimens shall be the actual thickness of the fabricated article and the width shall be one inch. Other dimensions of specimens shall be as designated by the ASTM standard. Specimens shall not be machined on the surface. Test shall be made with the inner side in compression using five specimens Flexural Modulus - The tangent modulus of elasticity in flexure shall be determined by ASTM Method D790. Copyright 2006 by International Association of Plumbing and Mechanical Officials. All rights reserved. Printed in the United States of America. No part of 7 of 13

8 Hardness - The Barcol Impressor (Model GYZJ 934-1) shall be used for determining hardness. Calibration of the Barcol instrument shall be verified by comparing with a blank specimen having a known reading of Ten (10) readings on the clean resinrich surface shall be made. After eliminating the two high and two low readings, the average of the remainder shall be the reported hardness reading. 4.3 Polyethylene The polyethylene used shall comply with ASTM Standard D 1248, Specification for Polyethylene Plastics Molding and Extrusion Materials, Class B (requiring an ultraviolet stabilizer) or Class C (requiring a minimum of 1% carbon black); D 1238, Test Methods for Flow Rates of Thermoplastics by Extrusion Plastometer; D 1505, Test Method for Density of Plastics by the Density Gradient Technique, and shall have a stress crack resistance of at least 150 hours when measured in accordance with ASTM Standard D 1693, Test Method for Environmental Stress-Cracking of Ethylene Plastics; D 1790, Test Method for Brittleness Temperature of Plastic Film by Impact and ASTM D 638, Test Method for Tensile Properties of Plastics The thickness of the side walls, top, bottom, and covers shall be at least 1/4 and the thickness of the inlet and outlet ends shall be at least 1/4 unless where engineering analysis can justify for lesser thickness. 4.4 Polypropylene - The polypropylene used shall comply with ASTM D 4101, specifications for Propylene Plastic Molding and Extrusion Material; ASTM D 1238, Test methods for Flow Rates of Thermoplastics by Extrusion Plastometer; ASTM D 1505, Test Method for Density of Plastics by the Density Gradient Technique; and ASTM D 638, Test Method for Tensile Properties of Plastics. The thickness of the sidewalls, top, bottom, and cover shall be at least inches, or if ribbing is employed, to be of equivalent strength except where engineering analysis can justify for lesser thickness. 4.5 Structural Foam - The raw structural foam material used shall comply with the requirments of Section and of this standard and the Melt Index Test in ASTM D Brittleness Test. During manufacturing the manufacture needs to perform a brittleness test at least once every shift. Pull a part hot off the press and place a sticker with the date, time and pallet number on it. This is to allow you to find the appropriate skids in event the part fails the Impact Dart Test. Verify that the correct dart is being used. The dart should be 10 lbs with a rounded head. The part must have cooled for one hour and be between degrees Fahrenheit before testing. Position the Basin, bottom up, under the impact tube with the tube resting in the middle of the basin bottom. Hook the 10 pound dart to the clip. Raise the 10 lbs. Dart to the premarked 5' drop line making sure the bottom of the dart lines up with the line on the tube and allow dart to fall onto part. After the impact inspect both the inside and outside of the part for any cracks or splits. Basin shall show no evidence of shattering,cracking or breaking Drop Test Method. The part must be between degrees Fahrenheit after 8 of 13

9 being removed from the mold before preforming the Impact Dart / Drop Test procedure. Hold the basin, bottom down, approximately 5 feet from the bottom of the unit, in the air and drop the part onto a concrete floor. Inspect each part after testing was preformed for cracks, chips, or breakage. 4.6 Alternate Materials Wooden tanks are prohibited. 5. TEST METHODS 5.1 Water Tightness Test for Sump or Sewage Ejector Tank. - Assemble the device according to manufacturers instructions, plug all openings except for the vent opening. Fill the tank with water until it approaches overflow at the vent opening. Leave the tank full of water for up to sixty (60) minutes and check for leaks. The vent opening pipe shall extend ten (10) feet above the cover during testing. 5.2 Stack Test for Sump or Sewage Ejector Tank. Assemble the tank according to manufacturer's instructions, plug all openings and attach stack pipe to one opening. Fill stack pipe to a height of ten feet. Leave tank full of water for up to twenty (20) minutes and evaluate for leaks. 5.3 Leakage/Water Tightness Test for Pump/Dose Tank. Tanks shall comply with the requirements in Section 5 of IAPMO/ANSI Z MARKING AND IDENTIFICATION 6.1 Each tank shall be plainly and permanently marked on the top with: (a) Manufacturer's name or trademark; (b) Model or catalog number; (c) Year of manufacture; (d) Above or Below ground installation;and (e) Wasteholding Tank or Pump/Dose Tank. 6.2 Each pump shall be plainly and permanently marked with the appropriate marking requirements specified within the UL Standard the pump complies with. Copyright 2006 by International Association of Plumbing and Mechanical Officials. All rights reserved. Printed in the United States of America. No part of 9 of 13

10 APPENDIX A A1 Chemical Resistance. ASTM Designation C 581, Tentative Method of Test for Chemical Resistance of Thermosetting Resins Used in Glass Fiber Reinforced Structures * is recommended for the evaluation of the chemical resistance of materials to be used in reinforced-polyester chemical-resistant process equipment. The reinforcing materials prescribed in the test laminate are only for the purpose of establishing a uniform basis for comparison. They may not necessarily represent the preferred materials for the particular environment. This procedure may be adapted to test or evaluate components, composition or fabrication variations and production samples. For information on the basis for selection of the standard test laminate, see Appendix of ASTM C 581. A1.1 The 10 Mil surfacing mat referred to in paragraph of ASTM C 581 shall be made of chemical resistant glass (Type C or equal). A1.2 The standard test laminate shall be cured at room temperature for 16 hours. Further cure shall be given at room or higher temperature, if necessary, to produce a Barcol Hardness in accordance with paragraph A2 A3 Temperature - Tests may be conducted at any or all of the following temperatures: 23 o C, 50 o C, 70 o C, 100 o C (+2 o C); reflux temperature; required service temperature. Reagents - The following reagents are suggested for use in obtaining general comparative chemical resistance data. The test solutions shall not be agitated; i.e., the exposures shall be under static conditions % Hydrochloric Acid 2. 25% Acetic Acid 3. 5% Sodium Hydroxide 4. 10% Sodium Carbonate 5. Saturated Sodium Chloride /4% Sodium Hypochloride ** 7. Distilled Water ** A4 A5 A6 Time - The properties specified in A5 shall be determined for specimens immersed in the test solutions for 30 days, 90 days, 180 days and one year, for one set of control specimens immediately following the curing period, and for another set after aging in air at the test temperature for the total test period. Properties - Thickness, Barcol Hardness, flexural strength and modulus, and appearance, shall be determined at each time interval. Appearance observations shall include any surface changes, color changes, obvious softening or hardening, crazing, delamination, exposure of fibers, or other effects indicative of complete degradation or potential failure. Calculation of percentage change in a property shall be based upon the property value obtained immediately following the curing period, i.e., unexposed laminate. Report - Data shall be reported in tabular form for all parameters tested. The composition, including resin, accelerators, catalysts and reinforcements, and the fabricating and curing conditions of the laminate tested, shall be adequately described. 10 of 13

11 IAPMO PS APPENDIX B An example of a polyester resin meeting the requirements is an isophthalic acid based chemically resistant type having an alkyd cooked using propylene glycol and an approximately 1/1 molar ratio of isophthalic acid and maleic anhydride or fumaric acid. The alkyd shall have a minimum molecular weight of 250, an acid number of less than 20 and a hydrosyl number of less than 45. The alkyd shall be combined with styrene monomer in proportions requisite to give the necessary working viscosity. The resin may also contain thixotropic additives as defined in and promoters for room temperature cures. Resin used for final surface coats on laminate surfaces exposed to air during cure may contain paraffin wax to prevent air inhibition. APPENDIX C C1 Pump. Grinder pump shall comply with UL 778 and shall be submersible duty rated. The pump shall be a centrifugal or semi-positive displacement type grinder pump, capable of grinding waste solids into a slurry. The grinder mechanism shall consist of stationary shredding ring and one or more rotating grinder impellers. The rotating grinder impeller shall be of a one piece design with multiple cutting surfaces in order to reduce the sewage to a fine slurry. C2 Piping. Discharge and vent piping and fitting shall be manufactured from approved materials for drain, waste and vent piping and in accordance with ASTM Specifications D 2661, D 2665, D 2949, D 3311, F 409 or F 628. Piping at all inlets and outlets to the basin shall be sealed watertight. C3 Gaskets. Cover gaskets shall be made from closed cell cross linked polyethylene foam material shall be per ASTM D All other basin penetrations shall be sealed with sealant tape or equivalent having a 0.39 GMS/24 hrs/m2 when tested in accordance with ASTM E 96 paragraph B. C4 Cord Seals. Cord seals molded from thermoplastic rubber shall be of Type C and Class E per ASTM D Backflow Prevention. The holding tank assembly shall be leak-proof and protected from backflow of sewage via a discharge check valve. C5 Control mechanism. All electrical components shall be listed by a nationally recognized testing agency complying with the applicable UL requirements. Pump(s) or system shall be controlled by means of an automated control panel that is activated either by a series of floats or via pressure transducer which are not integral to the pump construction. All portions of the control system which are located within the basin shall be removable for calibration, servicing, and repair 11 of 13

12 without removal of any portion of the pump or piping system. The control panel shall provide functionality to turn the pump(s) on and off based on water levels in the tank. The control system shall also have an integrated alarm that is triggered upon high water level in the basin. C6 Junction Box. Electrical junction box (if supplied) shall be a minimum NEMA type 6 in accordance with NEMA 250. C7 Anti-Siphon. Discharge piping shall contain an anti-siphon device consisting of a check valve plumbed in parallel and in reverse flow direction to the primary flow. The anti-siphon device shall not leak during normal pump operation, but shall open and vent to atmosphere when the pump is off. C8 Shut Off Valve. Shut off valve shall be either PVC or stainless ¼ turn or brass gate valve. C9 Controls. Controls shall automatically turn pump off and on based upon the liquid level in the basin. Controls shall also provide high water alarm function. Controls shall comply with UL 508A for non-hazardous locations or UL 698A for hazardous locations. C10 Quick Disconnect. If supplied, the quick connect plug shall be water tight and comply with NEMA 6P and/or IP-68 in accordance with NEMA 250 and/or IEC C11 Vent. Basin shall vent back through the inlet pipe and building vent stack or by a vent integrated into the cover assembly. C12 Preparation of Sample. Sewage holding tank shall be tested for hydrostatic pressure and external loading. The test tank sample shall be tested without the pump or controls installed. The four (4) inch inlet hole shall be sealed with an expandable plumbers plug. The sealed access cover shall be installed. The vent pipe shall be installed and extended to ten (10) feet in height. The discharge pipe opening shall contain a short section of pipe capped with a suitable means for removing trapped air in the upper portion of the pipe. Load test shall be performed before the hydrostatic test on the same unit. C13 Load Test. The tank shall be sealed then connected to a vacuum source. The basin shall be subjected to a vacuum of 12 inches of Mercury (Hg) for a period of one (1) hour in order to simulate external hydraulic loading. The side walls or basin bottom shall not deflect more than 8mm. No cracks or breaks shall appear on the tank surface after this test. C14 Hydrostatic Test. The test tank shall be filled with water at 72 F (22.2 C) and purged of air. Water shall extend up the vent pipe to a level of ten (10) feet (4.33 psi) from the floor. The tank or seals shall not leak for a period of fifteen (15) minutes duration. Any adjustments to seals or gaskets shall be completed prior to the fifteen (15) minutes duration test. 12 of 13

13 C15 System Submergence Test. The system shall be tested and comply with all requirements in Section 38 of UL 778. C16 Alarm Activation Test. The pump and control system shall be turned on and the tank shall be filled with water. Having preset the high level mark on the basin at which the control shall to turn off the pump and higher mark at which the high water alarm shall sound, verify that the pump shuts off at the appropriate mark and verify that the integrated alarm triggers upon reaching a preset high water level mark above normal pump shut off level mark. This test shall be repeated using an additional 4 different alarm, high, and low levels. System shall fail if not operating as intended by manufacturer. Adopted: 1992 Revised: 1996, 1999, 2004, 2005, 2006, 2009 editorial revision: June, This resin-rich surface layer will usually contain less than 20 percent of reinforcing material. A specific limit is not included because of the impracticability of determining this value in the finished product. * This method is based on a test procedure developed by the Reinforced-Plastic-Corrosion-Resistant Structures Subcommittee of the Society of the Plastic Industry, Inc. ** Replaced every 48 hours with fresh material. Copyright by International Association of Plumbing and Mechanical Officials. All rights reserved. Printed in the United States of America. No part of 13 of 13