The technical requirements for the piping components are mentioned in my earlier post. Click here to refresh those requirements. Additional to those requirements, the Requisition Engineer should include the inspection & testing, marking & colour coding and packing & preservation requirements in the purchase requisition.
Requisition engineer has to collate all the inspection & testing requirement for the piping components from the project specification & finalize the schedule in consultation with the quality department.
For marking, colour coding, packing & preservation requirements requisition engineer will refer the project specification & if that is not available he has to develop the standard procedure based on the company standard.
Inspection & Testing:
- All piping and fittings shall be inspected and tested in accordance with the relevant product standard (or code) and as stated in the Purchase requisition.
- Pressure testing (Hydro-testing) of stainless steel products where required by the standard shall be performed using water having less than 30ppm of chlorides.
- All welds in pipes & fittings shall be 100% radiographed in accordance with the individual ASTM Standard. Ultrasonic examination in lieu of radiography is not allowed.
- Examinations and/or tests may be reviewed and / or witnessed by the contractor or their authorized third party inspector at the vendor’s facility.
- The vendor is responsible for informing the contractor about the availability of goods for inspection and testing.
- Inspection shall be performed as per “Vendor Quality Requirement form” attached with the Inquiry / Purchase requisition.
- The manufacturer shall submit the certificate of conformity of the material duly certified by inspector.
Marking & Colour Coding:
- Marking of the piping components shall be done as per applicable codes and standards in addition to piping item/part number, purchase order number specified in Material Requisition Scope of supply. For the material specified as sour service, Low Temperature (LT), CRYOGENIC in Material Requisition Scope of supply, the marking shall include “Sour”, “LT”, and “CRYO” respectively.
- If punching or die stamping is used for carbon, low temperature and alloy steel, the stamps shall be of low-stress stamps (dot or round bottomed). For stainless steel stamping shall be electro etched. If stenciling is used, it shall be done by indelible paint. For sizes below 1.1/2” and below the markings shall be done on attached metal tags.
- Colour coding of piping components shall be done based on the material categories as identified in project specification attached with Inquiry / Purchase requisition.
Packing & Preservation:
- Material shall be packed ready for export in a manner which allows easy handling and prevents damage. Vendor shall submit their standard packing procedure to purchaser for approval.
- Pipe ends shall be protected with heavy duty plastic end caps. For bevelled ends, the caps shall cover the full area of the bevel.
- Thin wall pipes shall not be overloaded with multi-layer of pipes while shipping. All thin wall pipes shall be braced suitably at the end to avoid ovality.
- Open ends of fittings and flanges shall be supplied with heavy duty plastic protective plugs or caps. For bevelled ends, the caps shall protect the full area of the bevel.
- Water proof barrier material shall be used for stainless steel materials to protect against chlorine attack by exposure to salt water atmosphere.
- Carbon steel and stainless steel items are not allowed to be stored together and shall be packed separately.