Perlite Loading of Process Equipment Jackets and Field-Erected Storage Tanks
- PURPOSE
1.1 This specification defines for the contractor the minimum requirements for furnishing and installing perlite powder insulation.
- SCOPE
2.1 The contractor shall furnish all material, labor, tools, and equipment required to insulate the process equipment jackets with perlite insulation in accordance with the contract drawings and specifications.
- RELATED DOCUMENTS
3.1 Engineering Documents
Perlite for Cold Box Insulation
3.2 U.S. Department of Labor – Occupational Safety and Health Administration (OSHA)
3.2.1 Title 29, Labor Code of Federal Regulations (CFR)
29 CFR Part 1910, Occupational Safety and Health Standards
29 CFR Part 1926, Safety and Health Regulations for Construction
- MATERIALS
4.1 When the perlite is expanded onsite, the contractor shall provide three one-pint samples of perlite for inspection by the representative. A sample shall be provided before installation, midway through installation, and at the completion of the perliting operation. For more information regarding requirements for perlite insulation material, see 4WCB-50001.
4.2 When perlite is provided in bags, the contractor shall provide samples for inspection by the representative. These samples shall be provided two weeks before the bags of perlite arrive at the job site. For more information regarding requirements for perlite insulation material, see 4WCB-50001.
- WORKMANSHIP AND PRACTICES
5.1 The contractor shall employ only labor which has been qualified by training and experience to capably perform the specific activities required to accomplish the work in a satisfactory manner.
5.2 It is extremely important that provisions be made by the contractor to prevent any water or other liquids from entering the equipment jackets or tanks while the interiors are being filled, or the filling process is temporarily suspended during: night shifts, inspection of internal components, or verification of perlite levels.
- PERSONNEL SAFETY
6.1 Perlite, being lightweight, will become airborne very easily. If it enters the respiratory tract or the eyes, it will cause irritation. Workers in areas of airborne perlite shall wear goggles and a cartridge filter-type dust mask (North model 3007 or equal disposable respirator). If a worker must enter an area with high concentrations of airborne perlite, a full-face, air purifying respirator equipped with cartridge dust filters (upper limit 0.05 milligrams per cubic meter dust) shall be used. North 7600 series with N-7500-83 cartridges or equal are acceptable.
6.2 Any employee using an air-purifying or a particulate protection respirator must be fit-tested before its use. Site personnel will normally be fit-tested and trained/retrained once a year or once per job site, depending on the job’s duration. Records of employee or visitor respirator fit testing, assignment, and training shall be kept. These requirements are in accordance with 29 CFR, 1910.134 and 1926.103.
6.2.1 There must be no interference with the mask seal in order to get a good fit. Temple pieces on glasses, facial hair, stubble, or the absence of dentures will all prevent a good seal, depending on respirator design. Small beards or mustaches which fit inside the seal area and do not lift the respirator from the face or sideburns outside the mask seal area are permissible. Bearded employees whose facial hair interferes with the mask seal either must shave before being fit- tested or not be used to perform this type of work.
6.3 Most respirators create additional resistance to breathing. A medical screening must be performed to ascertain that person’s ability to perform the required extra physical effort. This screening record should be documented and kept on file.
6.4 Perlite being filled within enclosures (such as column cans, cold boxes, and tanks):
- Will not support the weight of a person, and thus precautions must be taken to ensure that someone cannot step, slip, or fall into it (for example, safety harnesses or substantial planking).
- Confined space entry procedures may be necessary based on specific work activities and shall meet 29 CFR 1910.146 and 4WCE-600700 or GEO EH&S procedures for work performed within existing GEO sites.
6.5 See 4WCE-600700 for other safety information that relates to this work scope.
7. EQUIPMENT
7.1 The contractor shall provide and maintain all tools and equipment in first-class condition and in sufficient quantities to assure successful performance and completion of the required work.
7.2 The contractor shall submit a written statement to Company defining the site requirements for all equipment.
- PROCEDURES FOR PROCESS EQUIPMENT (for example, COLUMN CANS AND COLD BOXES)
8.1 Before commencement of installation, the contractor shall submit a written statement to Company defining a proposed method of supply of expanded or unexpanded perlite to site. The containment method of supplied material (for example, bags or tanker) should be described. It should also include the origin of virgin rock and water content (%) of the rock. It should also define a location of expansion equipment and conveying method. If pneumatic conveying is used, probable air velocities should be provided.
8.2 The contractor shall exercise caution to prevent damaging the process components, piping, and instrumentation elements. Any damage caused directly or indirectly by the contractor’s labor, tools, or equipment shall be repaired or replaced at no extra cost to Company.
8.2.1 The contractor shall maintain a pressure of 0.345 bar g (5 psig) on all circuits in the process equipment. Any leaks created in the circuits during perliting will show up as a loss in pressure.
8.2.2 The contractor shall check electrical continuity through both leads of all thermocouples of the cold box before, during, and after the perlite insulation. Any reading that indicates an open circuit must be immediately brought to the attention of the Company representative.
8.3 The interior of the process equipment jacket shall be cleaned by others. The perlite contractor shall exercise precaution to prevent entrance of any foreign material during and after completing the operation. The interior of the process equipment jacket must be kept free of all foreign material including (but not limited to) wood, paper, rags, oily waste, or metal scraps.
8.4 The contractor shall not proceed with the installation of the perlite in the process equipment jacket until all piping and equipment has been pressure tested, and approval to proceed has been given by the Company representative.
8.5 The density of perlite, before filling any enclosure, shall be 40 to 48 kg/m3 (2.5 to 3.0 lb/ft3).
8.5.1 The contractor shall install the perlite to a density that shall not exceed 55 kg/m3 (3.4 lb/ft3). Higher compacted densities may be used with written consent of Company. Densities greater than 72 kg/m3 (4.5 lb/ft3) shall not be accepted. The perlite shall be vibrated by means of hammering the outer shell of the can or cold box with a rubber mallet or with a mechanical vibrator during perlite installation. Voids are not permitted.
8.6 The contractor shall remove access panels before installation of perlite and shall reinstall and make weather-tight after perliting.
8.7 The contractor shall keep the perlite dry and clean at all times. If the perlite becomes wet or contaminated, it shall be removed and replaced by the contractor.
8.8 It shall be the contractor’s responsibility to provide safe access to the cold box fill ports for workers, equipment, and materials.
8.9 The contractor shall take all precautions necessary to prevent the perlite from becoming airborne.
8.10 The contractor shall not proceed with perlite loading until valve cages/boxes have been installed, packed with rock wool, covered with blanket type insulation, seams sealed, and approval to proceed has been given by the Company representative.
- PROCEDURES FOR FLAT BOTTOM STORAGE TANKS
9.1 Before commencement of installation, the contractor shall submit a written statement to Company defining a proposed method of supply of expanded or unexpanded perlite to site. The containment method of supplied material (for example, bags or tanker) should be described. The proper set up of the tank pressure safety systems shall be addressed. It should also include the origin of virgin rock and water content (%) of the rock. It should also define a location of expansion equipment and conveying method. If pneumatic conveying is used, probable air velocities should be provided.
9.2 Inspect annular space to ensure cleanliness and that the space is ready to receive perlite. Verify outer tank piping penetrations are packed with rock wool.
9.3 Install temporary “goose neck” piping on the breather valve nozzle of the annular space.
9.4 The outer tank manway shall be used for perlite filling. This allows the annular space emergency vent to stay in service to provide over-pressurization protection during filling.
9.5 Pressurize the inner vessel to 0.069 bar g (1 psig) with dry, oil-free air or nitrogen and maintain this internal pressure during the perlite filling operation. The contractor must ensure that all inner vessel relief devices are installed and functioning properly. The pressure source shall not be left unattended during gas injection into the inner vessel. The pressure shall be checked every six hours, at a minimum, to ensure it is maintained at adequate levels.
9.6 The contractor shall submit to the Company representative a plan on how to control dust emissions that considers means of filtering, collection containers, and periodic changing of the filters. Suitable means to suppress dust emissions from the “goose neck” noted in paragraph 9.2. Sealing of annular space valve outlets is strictly prohibited, as they may result in an over- pressurization condition.
9.7 The contractor shall install the perlite to a density that shall not exceed 55 kg/m3 (3.4 lb/ft3). Higher compacted densities may be used with written consent of Company. Densities greater than 72 kg/m3 (4.5 lb/ft3) shall not be accepted. The perlite shall be vibrated by means of hammering the outer shell of the tank or jacket with a rubber mallet or with a mechanical vibrator during perlite installation. Voids are not permitted.
9.7.1 The density shall be certified by the perlite contractor by calculating the weight of perlite installed in the tank or jacket, divided by the calculated jacket volume. This includes small losses that may have occurred through the goose neck or hose leakage.