What is the danger if the valve does not close?

Gas may continue into the burner, causing failure to shut off, odor, flash ignition or poisoning risk. Shut the upstream gas supply and ventilate if closure is suspect. Checklist: Define capacity, accuracy, materials and operating environment before requesting quotes on a uniform basis. Request specification sheets, test reports, certificates, maintenance manuals and spare-part lists. During acceptance, verify appearance, dimensions, functions, safety protection and packaging, and keep test records. Do not compare unit price alone; include customization, freight, spare parts, after-sales support and downtime risk. Keep written records of inquiries, confirmations, FAT, acceptance and warranty commitments.