AWWA C504 butterfly valve has two forms, midline line soft seal and double eccentric soft seal, usually, the price of midline soft seal will be cheaper than the double eccentric, of course, this is generally done according to the requirements of customers. Usually the working pressure for AWWA C504 are 125psi, 150psi, 250psi, flange connection pressure rate are CL125,CL150,CL250.