Repair and requalification of LPG cylinders

Q. Alberto del Pilar, a retired general manager of Camara Steel Industries, Inc. and Jacinto Container Corp. seeks clarification on the March 3 Consumer Voice item on the repair and requalification of LPG cylinders.

A. The DTI has discussed with Mr. Del Pilar his concerns last March 14 at the DTI Office in Makati.

= The column seems to be saying that cylinders or bottles can be repaired and any part could be replaced, as if it is the best option to be resorted to. It seems to be extolling requalification or requalifiers. The column kept on saying that repair shops have DTI-Bureau of Product Standards certification. A cylinder, according to the column, can be repaired to remove or replace parts or attachments that are defective, a simple operation like welding, cup replacement, collar and footring replacement, and dent removal. For me, damaged or defective cylinders ought to be destroyed and scrapped immediately.

As required by Philippine National Standard (PNS) 03:2000, damaged or defective LPG cylinders are destroyed immediately.

Guided by the standards for the requalification of LPG cylinders, PNS 3 Part 2:2000, and DTI-Department Administrative Order 2:2002, the DTI monitoring teams look for external inspection defects. If an LPG cylinder exceeds the maximum limit of dents, bulges, etc., the cylinder is considered substandard and will be crushed. However, a cylinder that passes the visual inspection but needs repair has to go through the procedures indicated in PNS 3 Part 3:2000 and undergoes hydrotesting.

Only those cylinders that pass the repair and requalification requirements are filled with LPG. Those cylinders that have failed will be crushed.

Requalification is a method or procedure by which a cylinder is inspected and retested to determine its acceptability for continued service. Repair is the removal and replacement of parts or attachments of LPG cylinders and other corrective measures specified in the standard.

The DTI has certified several repair shops of LPG cylinders. These are: (1) Asephil Manufacturing Corp., with outlets in Mandaue City, Cebu; Calamba, Laguna; and Antipolo, Rizal; (2) Goodwill Metal Corp. in Pura, Tarlac; (3) Manifold Construction Enterprises, Inc. in Valenzuela City; and (4) Summit Metal Works Industries, Inc. in Taguig, Metro Manila.

= After the welding, random tests are conducted to see if pin holes, which are welding defects, are present. Ordinary welding and procedures are a no-no. It would be wise for DTI inspectors to look for such welding machines, wires, fluxes, the UT equipment, a normalizing equipment furnace capable of a continuous 500-degree Celsius temperature and various other testing equipment.

Based on PNB 3:2000, LPG cylinders are 100% hydrotested for leakages at twice the design pressure for 30 seconds, not randomly hydrotested. Also, only the submerged arc welding machine is acceptable for repair shops to use in repairing an LPG cylinder. After welding, the cylinder is annealed at a minimum of 650-degree Celsius temperature, not at 500-degree Celsius, for 15 minutes.

= Ideally, the lower cap replacement should never be resorted to. If it is resorted to, the replacement should come from the same coil, or at least having the chemical and mechanical properties as the original, which is impossible.

Another problem is the collar and footring replacement as well as the pipe and valve replacement. To reduce costs, some may be using thinner sheets for collars and footrings called Sch.40 instead of Scho. 80 pipes and second-hand valves worth P40 instead of new ones worth P120.

As indicated in the standard, PNS 3 Part 3:2000, the steel materials for fabrication intended for replacement of defective parts or attachments of LPG cylinders, such as the lower cap, collar, and footring, shall be compatible with the parent metal of the cylinder.

(You may send your consumer complaints and comments to the Bureau of Trade Regulation and Consumer Protection, DTI-Domestic Bldg., 361 Sen. Gil Puyat Ave., Makati City. You may also call us at our consumer hotlines 896-5740 or 890-4938. Our e-mail address is www.e-reklamo.net.ph)