Method for Wrapping Coating & Holiday Test for Fire Fighting Pipe

METHOD FOR WRAPPING COATING & HOLIDAY TEST FOR FIRE FIGHTING PIPE

August 3, 2021 1 Comment

PURPOSE:

This method describes the detailed procedure for installation & Testing of Wrapping Coating and Holiday Test for Fire Pipes as per the standard Practice and Codes.

GENERAL EQUIPMENT & TOOLS:

The equipment that will be engaged for Installation of Fire Pipe works will be * Tool Box * Welding Machine * Grinding Machine * Cutting Machine * Chain Block * Pipe Wrench * Hand Tools-gloves. * Hammer * Portable Lights * Manual Excavation Tools * Removable Barricades * Scaffolding / Mobile scaffold * Ladder * Spirit Level * Marker * Holiday Test Machine * Measuring tape

STORAGE & MATERIAL HANDLING:

The storage area must be free from dust and the materials should be stacked in proper manner to avoid any damages. * The material shall be transported in their original packing to Site location. * All materials shall be stored in a covered warehouse in a location as cool as possible and protected from the ingress of dirt, dust, moisture, etc. * Any coating materials show evidence of deterioration due to weathering or damage due to mishandling while are in the custody contractor, shall be replaced by the contractor. * Chemicals must be stored in well ventilated location and away from direct sunlight.

INSPECTION OF MATERIALS

Inspection of Wrapping Coating: * Check the reference of delivered material against approved submittal. * Check the material against the purchase order. * Check Type of Material ,Size of Material , Make of Material * Chemicals such as paints, primer and thinner, check their expiration date before receiving. * Physical Damages Inspection: * In case of any damages observed during inspection, the Material shall be returned to the supplier for replacement.

SEQUENCES OF WRAPPING WORKS:

(A) SURFACE PREPARATIONS:

Prior to brush cleaning, all oil, grease on the pipe surface shall be thoroughly removed by flushing with suitable solvent and wiping with clean tags. * Rusted materials surface shall be adequate scrubbed manually with stiff wire brush where ever surface get rusted, prior to application of primer. * Surface shall be completely free from rust, mill scale, grease, weld spatter, weld slag, dirt, dust, oil and any other foreign matter and to be dry at time of application. * Oil and grease shall be removed using an approved solvent. White spirit and paint thinners are suitable solvents. Kerosene shall not be used. * Mechanical cleaning machines shall not employ knives or other tools, which may produce notches or gauges on the pipe surface. * Blast cleaning machines shall be maintained in correct adjustment and replacement tools shall be available throughout the cleaning process. * All weld joints shall be cleaned manually with stiff wire brush/buffing * The coat of primer shall be given as soon as practicable and before detrimental corrosion or recontamination occurs. The cleaned surface shall never be left unprotected overnight. * The cleaning method employed shall not result in thinning of the pipe wall beyond the limits of the pipe specification. * Cleaning shall be carried out immediately before application of the priming coat and shall be to the satisfaction of OWNER. If the outside of the pipe becomes contaminated with any foreign matter.

(B) APPLICATION OF PRIMER:

Immediately after cleaning the surface shall be applied with one coat of primer before application of coal tar wrapping. The entire surface of pipe should be primed. * The primer shall be applied in a thin layer without runs, sags, drips, holidays (gaps or voids) or other defects. * If any defects may be found in the primed surface, the pipe shall be re-cleaned and primed to the required standard and to the satisfaction of principal/engineer. * No specific time gap between two coats needs to be maintained but after the coat of primer, the coating should before the primer is completely hardened. * The primer shall be suitable for brush or spray application and still form at thin uniform coating with an approximate 40 micrometer dry film thickness according to vendor’s instruction. * Freshly primed pipe shall be properly supported on racks, and allowed to be uncontaminated by moisture, dirt or other foreign matter. * If application is done in cold weather, the surface of the pipe shall be pre- heated until it is warm to touch and traces of moisture are removed and then primer shall be applied and allowed to dry. * Coating and wrapping shall not be started until that section of line has been tested and accepted. * The primer shall be suitable for brush or spray application and still form at thin uniform coating with an approximate 40 micrometer dry film thickness according to vendor’s instruction. * Primer shall be applied at an average rate 0.12 liter per…