MECHANICAL CONTRACTORS ASSOCIATION OF AMERICA, INC. CLEANROOM PIPING AND PROCEDURES BASIC CONSIDERATIONS

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1 BASIC CONSIDERATIONS For the mechanical contractor, cleanroom construction involves the installation of high purity piping which support an ultra clean environment. This involves extremely stringent requirements which the installing contractor does not deal with on the average mechanical system common to the industry. The following is an outline of items which are beyond the actual installation labor that a contractor bidding on cleanroom work needs to be aware of. These items are, with some variation depending on user requirements, commonly found in most project specifications that involve high purity piping: A. PROJECT SPECIFICATIONS. Due to the nature of these systems, it is important to thoroughly understand requirements and scope of work for each system. Be aware of code requirements for polyvinyldene (PVDF), piping, brazing, orbital welding, and stainless steel Gas Tungsten Arc Welding (GTAW). B. QUALITY ASSURANCE AND CONTROL. This is probably the most critical and important activity in cleanroom construction. There is an endless variety of high purity applications for piping materials in many industries including semi-conductor and pharmaceutical applications. Each situation must be analyzed as to the purity requirements. There is no convenient and meaningful way to monitor for all possible contaminants in a system. Therefore, it is most important to prevent contamination from entering the system before and after installation and during the movement form source to process. To ensure that proper quality control is achieved it is strongly recommended that one or several qualified individuals be assigned to the project to coordinate procedures and, even more important, to establish an interface with the owners quality assurance and control personnel. Some of the functions to be performed by quality control and assurance personnel are: 1. Ascertain and confirm the degree of purity required for the project. 2. Identify equipment needed to attain the degree of purity. 3. Establish procedures and methods to meet purity requirements. 4. Identify cleaning required to meet purity requirements. 5. Identify vendors who can meet specified material requirements on time. 6. Establish testing requirements i.e. where, when and how often. 7. Set up documentation and record keeping procedures (See list of typical forms under REPORTS/LOGS ). 8. Set up procedures for inspecting and monitoring of purge gas.

2 C. WELDING PROCEDURES AND WELDER QUALIFICATIONS. Joining of the high purity piping requires some type of welding. To meet the requirements of the applicable Codes, the installing contractor will be required to have both qualified welding procedures as well as qualified welders/welding operators. The following items should be considered: 1. Initial qualification and currency of welders. 2. Requirements for and frequency of daily tests. 3. Procedures and requirements for evaluation welded coupons. 4. Procedures for certifying welding machines and operators. 5. Recertification of welding machines after interruptions in use. 6. Operator experience (some project specifications require tow years or more of experience). 7. Record keeping on all aspects of welding, equipment tests and operator qualifications. D. TOOLS AND EQUIPMENT. Cleanroom projects require special tools and equipment which are not normally part of the average mechanical contractors inventory. These items would have to be either leased or purchased. Refer to the list of typical equipment requirements. In addition, the following issues need to be considered: 1. Review of project specifications to identify specific tool and equipment requirements. 2. All tools for cleanroom installation shall be pre-cleaned and used only in the cleanroom. 3. Policy and procedure for the care and storage of equipment and tools. 4. Maintaining the required cleanliness of tools and equipment. 5. Record keeping of tool and equipment usage, condition, status, etc. 6. Verification of equipment functioning to include test results. E. TEMPORARY CLEANROOM FACILITIES AND INSPECTIONS. Temporary cleanroom facilities must be established at the project site where all fabrication of component parts and storage of materials is maintained until they are installed in the project. Certain considerations are necessary for the proper functioning of these areas: 1. If a central power and collection unit with a distribution hose system is not available, a portable unit equipped with cleanroom post filtration of 0.3 microns should be used. 2. Procedures for monitoring the processes used in the fabrication area. 3. Procedures for monitoring the processes used in the cleaning area. 4. Record keeping of all inspections and monitoring results.

3 F. MATERIALS. Materials used in the construction of cleanroom facilities may be contractor furnished or owner furnished. In either case, standard operating procedures must be established to ensure proper materials are ordered and received from the suppliers. Consider the following items: 1. If owner furnished, make certain that the item(s) have been under control of owner s quality control procedures - verify and confirm that mill certificates are correct. 2. Contractor furnished verify and confirm mill certificates. 3. Ensure materials are stored in special material storage areas that meet the cleanroom class requirements. 4. Know material cleaning medium requirements. 5. Make sure vendors/suppliers totally understand the material specification requirements, i.e. high quality and cleanliness. 6. Maintain detailed records on all material orders and receipts. 7. Determine lead time for material orders cleanroom materials fall into a special category that is not commonly carried by vendors. G. RECEIVING INSPECTIONS. Another critical event in cleanroom construction is the delivery of materials to the project site. Extreme caution must be exercised during the receiving inspection. Make certain that the following is done as a minimum: 1. Inspect shipment for damage to containment covers. 2. Match shipment to purchase order and certification log (mill certificate). 3. Keep records of all receiving inspections. H. MATERIALS HANDLING. Removing materials from storage and doing the necessary fabricating before installation is an extremely sensitive event since at this point the materials are removed from their shipping containers and exposed to the environment. This requires that the personnel handling the materials have the proper clothing and equipment and that the operations are performed in specially constructed and environmentally controlled facilities. Record keeping becomes essential during this phase. Following records and other considerations are suggested: 1. Materials inspection log 2. Procedure documentation log 3. Cleanliness certification log 4. Availability of special handling tools and equipment (See list on page 11) 5. Record of methods used

4 I. TESTING. Testing of the installed system must be carefully planned and executed to avoid impurities in the system. Consider the following items: 1. Purge Gas - a. Make sure cylinders have not been damaged or show signs of leakage. b. Make sure monitoring devices are installed at required locations. c. Make sure the project specifications have been reviewed for any special requirements. 2. Incremental Testing - a. Test system in increments and seal properly to avoid contamination. b. Get owner representative to sign off on sections tested. c. Keep records of all tests performed. J. SAFETY. Cleanroom construction involves hazardous chemicals that personnel handling them must be made aware of. This requires a well thought out and detailed jobsite safety and health program in accordance with the OSHA Hazard Communication Standard. Because of the potential chemical spill, prevention and disposal requirements as established by the Environmental Protection Agency (EPA) also need to be taken into consideration. The following items, as a minimum, need to be considered to ensure a safe and healthy workplace: 1. Availability of and compliance with a written company safety program. 2. Availability of and compliance with a written company hazard communication program. 3. Program for the disposal of chemicals used for cleaning and testing. 4. Program for disposal of scrap. 5. Designation of a project safety and health manager and competent persons as necessary. 6. Confined space entry procedures. 7. Emergency procedures for containing hazardous gas and chemical leaks. 8. Comprehensive employee training program. 9. Personal protective equipment requirements. 10. Written inspection and testing procedures. 11. Procedures for notifying other contractors in case of emergency. K. CLEANROOM PROCEDURES. Cleanroom procedures should be developed and implemented to ensure that all personnel who work on the fabrication and installation of cleanroom systems have a uniform understanding of the activities and actions that must be observed when in or near cleanroom areas. Some requirements that should be included in these procedures are as follows:

5 1. General a. All particulate generating fabrication shall take place outside the particulate controlled area unless specifically authorized. b. All materials brought into the clean space shall meet minimum cleanliness standards on both their exterior and interior surfaces. 2. Cleanroom Areas a. The established level of cleanliness shall be monitored using spot checks at prescribed locations. b. All entrances and exits to the cleanroom shall be controlled with entry restricted to badged personnel. c. Active contamination controls, such as tacky mats, shall be placed in designated areas. d. Personnel who are pre-qualified to work within the clean space shall be badged. e. Personnel working in the clean space shall wear cleanroom garments. f. Smocks and hood shall be worn completely closed at all times. g. Only approved footwear will be allowed in clean areas. h. Food and drink shall not be brought into the cleanroom area. i. Smoking shall not be allowed in the cleanroom area. j. No pencils shall be allowed in cleanroom areas. k. No personal effects shall be allowed in the fabrication area. l. Safety glasses shall be worn in and in route to clean room areas. m. All equipment shall, at all times, be protected with visqueen when work is being done inside the fabrication area. 3. Gown Areas a. Gown areas are extensions of the cleanroom areas and should be the same rules as for cleanrooms. b. Foot scrubbers should be used before entering the gown area. c. Items not allowed in the cleanroom area should not be brought past the gown area. 4. Subcontractors and Visitors a. Subcontractors shall conform to all established cleanroom procedures.

6 b. All materials brought into the cleanroom by subcontractors for installation shall be properly wiped down. c. All visitors shall be escorted and shall comply with all established cleanroom procedures.