Piping Technology and Products, Inc. designed and manufactured furnace spring assemblies for a chemical refinery in Saudi Arabia.  Each assembly consists of a variable spring, rod, clevis, hex nuts, and pipe attachments. Unlike other variable springs which are designed to have bolted housings, these furnace springs are designed for spring coils with a customer specified spring rate installed in a welded housing. The sizes of these Fig. PTP-2 and Fig. PTP-4 ranged from 90-170, with a total travel of 1 1/4" to 5", and loads varying from 850 lbs to 13,300 lbs.

Prior to the final welding, trial fit-up and cycle test were performed to ensure unrestrained movement throughout the designed travel range. The spring assemblies were then calibrated to determine the exact spring rate prior to shipping.