Yes. Cherne offers two chemical resistant mechanical plugs: The Cherne Well Monitor Plug and the Cherne Petro Econ-O–Grip.

There are patch kits available for Urethane plugs. Other plugs that can be patched or have the bag replaced, are as follows; 15"–30", 24"–42", 20"–40", 24"–48", 24"–60", 48"–72" and 54"–96"

Generally speaking pneumatic plugs that don’t have sealing rings may be eligible for patching. The damage to the plug cannot be any longer than 4", or deep enough to penetrate the cording. Plugs cannot be patched more than 4 times. Other repairs can also be made, like replacing inflatable bladders, bypass hoses, castings and fittings. When in doubt, ask the customer to take digital pictures of the damaged area and email it to you. Forward the pictures to the Cherne QA Dept. along with a description of the damage for final determination.

Yes. Cherne publishes a chart that pairs up our pneumatic pipe plugs with some of the most popular sizes of elliptical pipes. It can be found on Cherne’s website at Oatey.com/Cherne.

Normal maximum temperature = 125° F. Normal minimum temperature = 0° F. Consult factory if you wish to use plug at temperatures outside this range.

Both our original long ball and our MS2 Long Balls are designed to seal wye fittings while conducting a sewer test. The MS2 Long Ball is unique as it features a relief valve, is multi-size, and inflates and deflates in stages to keep the work area dry by keeping the water from coming up through the pipe riser during the deflation process.

Date codes on small test balls/long balls are two digit numbers (ex. 14). Date codes are changed each year on July 1st. Plugs manufactured on/after July 1st will bear the last two digits of the next year (ex. Plug manufactured on July 1st, 2014 would have a date code of 15). Larger plugs have the date codes stamped on the front of the plug. It will begin with the year, followed by a letter indicating the month, followed by a number for the day, and a letter for the unit produced. Example for a plug manufactured on February 14th, 2015 would read 15B14A.

Concrete pipe is porous and the ASTM guidelines give allowances for this porosity.

Owner’s Manuals and parts lists on all Cherne equipment can be located in the technical section of the Cherne website.

Backpressure is measured either in terms of feet of head or psi.

• Feet of Head. Simply stated “feet of head” is the height of water above the centerline of a plug. For vertical pipe the calculation is easy. Simply measure the height of the pipe and that is the footage of head pressure. For horizontal pipe, feet of head is still simply the height of water above the plug. There are various ways to determine this height base on knowledge of the actual application. For example, if you have a 300' long section of pipe at a 1 degree slope, the feet of head is 3'.  (300*.01)
• PSI - This measurement is typically done with a pressure gauge.
• #’s (pounds) of Force. This is the calculation to determine how much force is being held back by a plug. It is useful information when trying to design a plug blocking system for a specific job.
  • Calculating pounds of force for air pressure tests. PSI (square inches of pipe opening) = #’s of force. Example: 8" and 5 PSI test. Pipe area = Pi R2 * (3.14*42=50.24").  50.24" * 5 PSI = 251.2 #’s of force.
  • Calculating pounds of force for head  pressure applications. Convert Feet of Head to PSI and then do calculation above. PSI = Feet of Head *.434.  Example: 8" pipe at 30' of head. Pipe area = Pi R2 * (3.14*42=.50.24") 30 Feet of Head *.434 = 13.02 13.02 *  50.24 = 654 lbs. of force.