Check Your Pigs Regularly: Urethane Pigs are a normal wear item in a pigging system. They need to be inspected periodically and replaced as needed. It is recommended that pigs be inspected once a month and replaced as necessary. Keep in mind that the number of times a pig runs in a day, week or month varies widely depending on the project/user. Using common sense as to the time frame for checking pigs based on your operation schedule will go a long way. As pig wiper discs approach a factor of 1.005x of the pipe ID, or show signs of tearing, cracking, etc., they should be replaced immediately.