August 2021, Vol. 248, No. 8
Tech Notes
Proper Cleaning and Storage of Pipeline Pigs
Special to P&GJ
Proper storage and maintenance are important to ensure the optimal performance and condition of urethane pigs.
Apache pigs will perform as designed for pipeline cleaning, batching and displacement. However, urethane components are subject to deterioration under certain conditions – namely, heat, humidity and UV light.
To keep your pigs in top shape, here are some guidelines you should follow for proper storage and cleaning of pipeline pigs:
As mentioned, heat and humidity will accelerate the deterioration of urethane pigs. You can maximize shelf life by maintaining a temperature between 27° C (80.6° F) and a relative humidity less than 60%.
You should keep your urethane pigs out of direct sunlight as the heat will affect the urethane. Should the urethane components be exposed to extreme cold, they should be warmed to between 10 and 27°C (50 – 80.6°F) before use, since cold will cause the urethane to become brittle.
Pig parts should also be stacked to prevent deformations of their shape – this is especially important for pig cups. Lastly, to maintain shelf inventory, use a “first in, first out” usage system.
Assembled Pigs
The ideal storage for pigs is on a stand with a stand supporting the pig weight. Brush and blade pigs should be stored standing on end. Otherwise, storing pigs with blades, springs or urethane cups on their sides will cause deformations of the cups and blades.
Removeable plug components need to be properly stored as well. Urethane pig cups can be stacked if the weight is not enough to distort the lowers cups. Urethane discs can be stacked as well. Any urethane parts that have been stored for six months or more should be examined for physical properties before being used.
Components that lose their physical properties will soften, darken in color, and begin to flake or crumble. Should this occur, these parts need to be discarded.
You should also check for hardness by using a sharp tool. When pressed into the urethane, the amount of penetration should be minimal.
You can also use a durometer gauge for a more precise measure of non- metallic hardness. A cup or disc component with a hardness outside of manufacturing specs should be discarded.
When in doubt, you can always contact the manufacturer for more information on the condition of your pig and pig- related products.
Cleaning
A pig needs to be cleaned as soon as possible after being removed from the pipeline. If the pig is heavily packed with paraffin, most of it can be removed by scraping immediately after the pig is removed from the trap.
Submerge the scraper in water heated to 70° C (158° F) for no more than an hour before scraping. Once the bulk of the paraffin has been removed, you can clean the remainder with high pressure water jet. A high-pressure jet can also be used to clean liquid residue from your pig.
Steam cleaning is acceptable for cleaning metal body parts and spring assemblies – but ONLY these parts! The maximum water temperature you should use is 85° C (185° F) for a maximum of 30 minutes. Any hotter, or longer could cause damage to exposed urethane.
You can also use solvents such as diesel fuel or kerosene to clean your pigs. Urethane components can be immersed in or wiped with either one.
The proper storage and cleaning of your pipeline pig inventory will save you both time and money! It will also ensure the maximum effectiveness of your pigging product and project.
if you have any questions about cleaning and storing your urethane pigs, feel free to contact our experts at Apache Pipeline Products.
Comments