HT-20B 20GAL BLADDER TANK WATERWORKER | Maximum 100 psi pressure rating for residential use. Heavy diaphragm designed for extended life, locking ring, high-grade polypropylene liner, durable steel base. NSF Standard 61 listed meets FDA requirements for potable water. Maximum operating temperature is 200 deg F. Factory pre-charged to 38 psi. Made in the USA. 5 year limited warranty.