1、 Standard Recommended Practice Field-Applied Underground Wax Coating Systems for Underground Pipelines: Application, Performance, and Quality Control This NACE International standard represents a consensus of those individual members who have reviewed this document, its scope, and provisions. Its ac
2、ceptance does not in any respect preclude anyone, whether he or she has adopted the standard or not, from manufacturing, marketing, purchasing, or using products, processes, or procedures not in conformance with this standard. Nothing contained in this NACE International standard is to be construed
3、as granting any right, by implication or otherwise, to manufacture, sell, or use in connection with any method, apparatus, or product covered by Letters Patent, or as indemnifying or protecting anyone against liability for infringement of Letters Patent. This standard represents minimum requirements
4、 and should in no way be interpreted as a restriction on the use of better procedures or materials. Neither is this standard intended to apply in all cases relating to the subject. Unpredictable circumstances may negate the usefulness of this standard in specific instances. NACE International assume
5、s no responsibility for the interpretation or use of this standard by other parties and accepts responsibility for only those official NACE International interpretations issued by NACE International in accordance with its governing procedures and policies which preclude the issuance of interpretatio
6、ns by individual volunteers. Users of this NACE International standard are responsible for reviewing appropriate health, safety, environmental, and regulatory documents and for determining their applicability in relation to this standard prior to its use. This NACE International standard may not nec
7、essarily address all potential health and safety problems or environmental hazards associated with the use of materials, equipment, and/or operations detailed or referred to within this standard. Users of this NACE International standard are also responsible for establishing appropriate health, safe
8、ty, and environmental protection practices, in consultation with appropriate regulatory authorities if necessary, to achieve compliance with any existing applicable regulatory requirements prior to the use of this standard. CAUTIONARY NOTICE: NACE International standards are subject to periodic revi
9、ew, and may be revised or withdrawn at any time. NACE International requires that action be taken to reaffirm, revise, or withdraw this standard no later than five years from the date of initial publication. The user is cautioned to obtain the latest edition. Purchasers of NACE International standar
10、ds may receive current information on all standards and other NACE International publications by contacting the NACE International FirstService Department, 1440 South Creek Drive, Houston, Texas 77084-4906 (telephone +1 281/228-6200). Revised 2006-03-11 Reaffirmed 1999-04-28 Revised October 1994 App
11、roved March 1975 NACE International 1440 South Creek Drive Houston, Texas 77084-4906 +1 281/228-6200 ISBN 1-57590-089-0 2006, NACE International NACE Standard RP0375-2006Item No. 21013RP0375-2006 NACE International i _ Foreword Wax coating systems are designed to provide underground pipes with prote
12、ction against corrosive environments. This standard recommended practice covers surface preparation, material requirements, application, and handling of hot- and cold-applied wax and component wrappers and wax-tape coating systems for the protection of underground pipe, fittings, and valves. This st
13、andard is intended for use by corrosion control personnel, design engineers, project managers, purchasers, and construction engineers and managers. This standard was originally prepared in 1975 by Task Group T-10D-16, a component of NACE International Unit Committee T-10D on Protective Coating Syste
14、ms. It superseded NACE Publication 2L161.1 The scope of the original NACE Standard RP0375 included only the application of hot- and cold-applied wax coatings. When this standard was revised by the task group in 1994, the section on wax-tape coatings was added. In 1999 this standard was reviewed by T
15、ask Group (TG) T-10D-17/T-6A-63 and reaffirmed with editorial changes. In 2005 it was revised by TG 296, which is administered by Specific Technology Group (STG) 03 on Protective Coatings and LiningsImmersion/Buried. It is also sponsored by STG 04 on Protective Coatings and LiningsSurface Preparatio
16、n, and STG 35 on Pipelines, Tanks, and Well Casings. This standard is issued by NACE International under the auspices of STG 03. In NACE standards, the terms shall, must, should, and may are used in accordance with the definitions of these terms in the NACE Publications Style Manual, 4th ed., Paragr
17、aph 7.4.1.9. Shall and must are used to state mandatory requirements. The term should is used to state something good and is recommended but is not mandatory. The term may is used to state something considered optional. _ RP0375-2006 ii NACE International _ NACE International Standard Recommended Pr
18、actice Field-Applied Underground Wax Coating Systems for Underground Pipelines: Application, Performance, and Quality Control Contents 1. General . 1 2. Hot-Applied Wax Systems 1 3. Cold-Applied Wax Systems 3 4. Cold-Applied Wax-Tape Coating Systems 4 5. Handling of Wax-Coating Piping . 6 6. Cathodi
19、c Protection of Wax-Coated Pipelines, Valves, and Fittings 6 References 7 Table 1: Requirements for Hot-Applied Wax. 1 Table 2: Property Values of Component Wrappers. 2 Table 3: Requirements for Cold-Applied Wax . 4 Table 4: Requirements for Wax Tape and Primer. 5 _ RP0375-2006 NACE International 1
20、_ Section 1: General 1.1 This standard covers hot- and cold-applied wax and component wrappers and wax-tape coating systems for the protection of underground metallic pipe, fittings, and valves. It outlines material requirements for hot-applied waxes, cold-applied waxes, component wrappers, and wax
21、tapes as well as proper methods of surface preparation, coating application, and handling of the coated pipe. 1.2 Tables 1 through 4 provide material requirements and give references to ASTM(1)standard test methods for the various coating materials discussed. 1.3 Any reference made to wax tape and w
22、ax primer in this standard also applies to petrolatum tape and petrolatum primer. 1.4 Hot-applied wax coatings may be applied by machine as a line-travel operation in the field or by hand. Cold-applied wax and wax-tape coatings are applied only by hand. These coatings may be used on new piping or fo
23、r coating rehabilitation. 1.5 The surface preparation required for hot-applied wax coatings differs from the surface preparation required for cold-applied wax and wax-tape coatings. _ Section 2: Hot-Applied Wax Systems 2.1 Hot-applied wax coating systems for underground pipes usually consist of a mi
24、crocrystalline wax coating applied directly to the surface followed by an overwrap of component wrapper. 2.2 Hot-applied wax coating materials shall have the following characteristics: 2.2.1 Microcrystalline Wax 2.2.1.1 Microcrystalline wax shall be inert, flexible, waterproof, adhesive, and have go
25、od wetting characteristics. 2.2.1.2 Microcrystalline wax shall be capable of being blended with suitable wetting agents and rust inhibitors. 2.2.1.3 Microcrystalline wax shall meet the requirements given in Table 1 when tested in accordance with the test methods listed therein. 2.2.1.4 Microcrystall
26、ine wax shall be heated or may be reheated in a clean kettle or a kettle that has been previously used for microcrystalline wax pipe coating. 2.2.1.5 Microcrystalline wax shall have service-temperature capability up to 52C (125F). Service-temperature properties shall be determined by the hot-applied
27、 wax conforming to properties listed in Table 1. TABLE 1 Requirements for Hot-Applied Wax Properties Physical Requirements Test MethodSpecific Gravity at 25C (77F) 0.85 to 0.92 ASTM D 702Needle Penetration at 25C (77F) 26 to 50 ASTM D 13213Melting Point 71 to 79C (160 to 175F) ASTM D 1274Flash Point
28、 260C (500F) minimum ASTM D 925Dielectric Strength 4 V/m (100 V/mil) minimum ASTM D 14962.2.2 Component Wrappers 2.2.2.1 Component wrappers shall consist of a wax-laminated plastic film, a wax-saturated mat, or extruded polyethylene on glass mesh that is compatible with the microcrystalline wax coat
29、ing. 2.2.2.2 Component wrappers shall be used over fittings and valves and have the ability to conform to the contours of the surface. 2.2.2.3 Component wrappers shall meet the requirements in Table 2 when tested in accordance with the test methods listed therein. _ (1)ASTM International, 100 Barr H
30、arbor Dr., West Conshohocken, PA 19428. RP0375-2006 2 NACE International 2.2.3 Additional outerwraps or rockshields may consist of suitable material such as kraft paper, glass cloth, or synthetic fiber mat, and may be used to assist in the prevention of handling or backfill damage and to help with v
31、isual detection of physical damage to the coating system. TABLE 2 Property Values of Component Wrappers PropertiesPhysical RequirementsTest MethodSupported WrapperWax-Laminated Plastic Film on Spun-Bonded Plastic Mat Plastic Film Thickness 13 to 25 m (0.5 to 1.0 mil) ASTM D 10007Wax Melt Point 71 to
32、 99C (160 to 210F) ASTM D 127 Average Thickness 300 m (12 mil) ASTM D 1000 Dielectric Strength 14 V/m (350 V/mil) minimum ASTM D 149 Supported WrapperWax-Saturated Spun-Bonded Plastic Mat Wax Melt Point 71 to 99C (160 to 210F) ASTM D 127 Total Thickness 250 to 640 m (10 to 25 mil) ASTM D 1000 Dielec
33、tric Strength 14 V/m (350 V/mil) minimum ASTM D 149 Supported Wrapper Extruded Polyethylene on Glass Mesh Polyethylene Film Thickness 50 to 150 m (2 to 6.0 mil) ASTM D 1000 Total Thickness 150 to 250 m (6.0 to 10 mil) ASTM D 1000 Dielectric Strength 28 V/m (710 V/mil) minimum ASTM D 149 2.3 Suggeste
34、d Application Systems 2.3.1 Traveling machine application (1) One coat of hot-applied wax coating; (2) One wrap of component wrapper; and (3) One wrap of suitable outerwrap (if specified). 2.3.2 Hand application (1) One coat of hot-applied wax coating; (2) One wrap of component wrapper; and (3) An a
35、dditional overcoat of hot-applied wax (if specified). 2.4 Surface Preparation 2.4.1 The surface shall be free from oil and grease and, if necessary, shall be solvent cleaned in accordance with SSPC(2)-SP 1.8 2.4.2 Unless otherwise specified, the surface shall be hand-tool cleaned in accordance with
36、SSPC-SP 2.9 2.4.3 The surface shall be dry prior to application of the coating. The pipe surface temperature shall be more than 3C (5F) above the dewpoint temperature. The pipe shall be heated to remove moisture. Coating application should follow immediately after preheating. 2.4.4 The prepared surf
37、ace shall be visually inspected to determine whether foreign material has been removed in accordance with the degree of cleanliness specified. 2.5 Coating Application 2.5.1 Hot wax shall be flooded directly on the surface at the temperature recommended by the manufacturer and approved by the enginee
38、r in charge or a representative of the owner. The application temperature range is based on ambient conditions and pipe temperature. 2.5.2 The temperature of the wax applied to the pipe surface shall be sufficiently hot to produce a continuous film of 500-m (20-mil) minimum thickness and adhere well
39、 to the surface. An infrared temperature gun or bulb thermometer may be used to measure the temperature of the wax and to ensure proper heating of the wax. A wet-film thickness gauge shall be used to measure thickness at the 12, 3, and 6 oclock positions on the pipe. _ (2)Society for Protective Coat
40、ings (SSPC), 40 24thSt., 6thFloor, Pittsburgh, PA 15222-4656. RP0375-2006 NACE International 3 2.5.3 Before starting to coat a full section of pipe, a 1-m (3-ft) section of pipe shall be coated and inspected for adhesion at the 12, 3, and 6 oclock positions. Using a field knife, the inspector shall
41、attempt to remove a 50- x 25-mm (2.0- x 1.0-in.) strip, consisting of a continuous and clean layer of wax, from the pipe surface. If the wax layer can be removed from the pipe surface in a continuous film with no visual evidence of a wax layer remaining on the pipe surface, then proper adhesion was
42、not achieved. If proper adhesion is not apparent, the temperature of the heating vessel containing the wax shall be raised 11C (20F) and the adhesion test shall be attempted again. The temperature shall continue to be increased in 11C (20F) increments until the wax adheres properly to the surface. W
43、hen the proper heating temperature of the coating has been achieved, coating of the pipe section may commence. At no time during the heating shall the temperature meet or exceed the flash point of the wax as shown in the manufacturers material safety data sheet (MSDS). Note: If proper adhesion is no
44、t achieved on the test section, the wax shall be removed in accordance with the manufacturers recommendation and reapplied to the test section at a higher temperature, as stated above. In addition, the operator may implement operational “workarounds” in conditions in which pipe may have moisture on
45、the surface due to pressure differentials (e.g., reduce product flow through the section of pipe to be coated in order to raise the pipe temperature). 2.5.4 The wrappers shall be applied in a uniform, snug-fitting, and overlapping pattern following the application of the hot wax coating. 2.5.4.1 Com
46、ponent wrappers are normally applied using a spiral wrap. Component wrappers may also be applied using a cigarette wrap technique as specified by the manufacturer. 2.5.4.2 Wrapper tension shall be sufficient to ensure tight application over the coating. 2.5.4.3 Overlap at the edges of the wrapper sh
47、all be maintained as recommended by the manufacturer and approved by the engineer in charge or a representative of the owner. Usually a minimum of 25 mm (1.0 in.) of overlap and 76 mm (3 in.) of existing coating is required. 2.5.5 Application of the wax coating and wrapper shall be visually inspecte
48、d to determine that the application conforms to contract specifications and is free from holidays or other coating irregularities. Flood coating the pipe with a method specified by the coating manufacturer shall be used to ensure adequate coverage. 2.5.6 The entire hot-applied microcrystalline wax system of each field application area may, at the purchasers option, be inspec
