Urethane PigsDecoking Pigs


Figure 1: Decoking Pigs


Decoking pigs are designed to remove very hard deposits, such as coke, in fired heaters, thus commonly referred to as “decoking pigs”.

There are various styles of decoking pigs on the market today. We manufactured from polyurethane using a foam core with the appendages sealed into the body of the pig. This urethane body allows the fluid to flow around the pig and with no saturation. Other types are manufactured from polyurethane foam in a 25-30 lb density per cu/ft with the appendages screwed into the body of the pig. Both types of “decoking pigs” are used in the same concept of progressive pigging with bypass for flow disposal of debris.

The Decoking pigs are made from various durometers of urethane, dependent upon compression requirements, with a foam core. The appendages are sealed into the body to eliminate appendages coming out of the body, ending up loose in the tubes.

Decoking pigs can be used for pipeline cleaning purposes for very hard deposits that other pigging products may not be able to remove, in a progressive pigging manner.

It is important to obtain technical assistance with regards to using appendage pigs in the pipeline for methods used in pushing the pig and flow rates required.


Figure 2: Appendages

There are 4 main appendage styles used for the progressive pigging method.
  • 1)1)Appendages 1, 2 & 3: flat head with grooving tip in 3 lengths creates groves in the deposit for layer removal of deposit
  • 2)Hardened metal bolt: used behind a grooving pig run to remove the layer created
  • 3)Spiral Bolt: used after line has been pigged with progressive pigging method for final cleaning
  • 4)Smooth Head: used for final polishing and testing to verify cleanliness
Before pipeline operations purchase “decoking” pigs to remove hard deposit build up, it is imperative to relay the necessary information to obtain the correct pigs for the application.
  • Pipe schedule
  • Wall thickness
  • Type of build up
  • Flow rate
  • Length of section to be pigged
  • Contents of line
  • T’s, short bends, 90s or 45s

Prior to obtaining or purchasing these pigs, we recommend speaking with a qualified technician for methods and procedures of this type of pigging.

(Referrals available)