For those who don’t know what compression packing is, this article is all you need.
Compression packing is simply one of the oldest but efficient ways of sealing devices. It is created from different packing fibers, and it helps to prevent products from leakages, and prolong the lives of pumps, valves, etc.
This packing is situated between the rotating member and the body of the pump or valve to create a seal and is compressed within the stuffing box. There are different fibers used: graphic packing, carbon packing, acrylic fiber packing, aramid packing, etc.
You must note the basic steps necessary for a complete compression packing installation.
Let’s look at them, shall we?
Basic steps for compression packing installation
The Selection Process
This step is very important as other steps depending on how effectively this is planned out. There are so many packing fibers, combinations of packing fiber materials, and braid configurations. It can be very difficult and confusing to select the right ones, especially as a beginner.
Now, you’d say that the manufacturer often attaches a specification guide to the product, but there are cases when you don’t have access to it. What do you do?
We use the STAMPS method. It’s a useful guideline that will help us to remember key considerations when choosing.
Size- what is the dimension of the stuffing box?
Temperature- How hot or cold is the medium? What temperature are you working with?
Application- Is it a valve, pump, or any other equipment?
Medium- what do you want to seal?
Pressure- what is the pressure range in the medium?
Speed- What speed does the surface shaft run on?
With these parameters, you have successfully considered chemical compatibility of the packing media, running temperature and pressure, shaft speed, and functionality of the equipment (valves or pumps)
The Preparation Stage
When you have selected the right packing material, prepare the pump (or valve) and its accessories for installation.
For instance, if there is a worn-out packing, it must be removed. The stuffing box should be properly cleaned. There should be no leftover debris that can cause unlevelled seating (this can lead to leakages and overheating problems).
After the preparation stage, the next stage is to determine whether the packing rings were formed by the packing supplier, or cut from bulk spools on-site. If it’s done on-site, make sure they size properly. The rings must fit the shaft’s size.
Don’t use an already-used packing ring to cut a new one. It may lead to a bad cut length because the used ring may have either reduced due to lubricant loss or stretched when removed.
This stage is another very important one. The first ring creates the alignment pattern for other rings to follow, so if it’s not placed properly, other rings will be negatively affected. The following can result:
· It can lead to excess leakage because of the gap the improperly placed first ring created
· The number of packing rings may no longer fit
Give enough time when breaking in a new packing substance. It needs multiple adjustments so the process requires patience. Just make sure that the packing isn’t overtightened.