Hydraulic Cylinder Guide: Seal Kits

Seal kits serve the purpose of sealing gaps between components within hydraulic cylinders. The closure of these gaps is of utmost importance, as seals play a crucial role in upholding hydraulic pressure and obstructing the infiltration of contaminants into fluid power systems.

Should you be contemplating the acquisition of a hydraulic cylinder seal kit, it is probable that you have queries that warrant clarification. This article aims to provide guidance on essential considerations to be made prior to finalizing your purchase.

ARE HYDRAULIC CYLINDER SEAL KITS UNIVERSAL?

In summary: No.

There exists a variety of hydraulic cylinder rebuild kits, each tailored to specific hydraulic cylinder specifications such as rod and bore diameters, stroke length, cylinder length, pressure flow requirements, among others. These kits include standard, loaded lip, cast-iron piston rings, and fluorocarbon seals.

The appropriate kit selection is contingent upon factors such as the stroking speed of the piston rod, fluid media, fluid pressure range, and other relevant considerations. Additionally, it is essential to ensure that the seals within the kit are appropriately sized for the specific hydraulic cylinder in question.

GUIDE TO CHOOSING THE APPROPRIATE SEAL SIZE

Determining the correct size for a hydraulic cylinder seal kit is a methodical process that requires the use of a tape measure and calipers for accurate measurements. It is advisable to proceed with caution and precision during this task.

Step 1: Determine the Bore Diameter

To begin, measure the bore diameter of the cylinder by using a tape measure stretched across the inner barrel.

Step 2: Measure the Piston Rod Diameter

Next, measure the diameter of the piston rod, typically a chrome-plated, circular hardened steel piece attached to the piston, using outside calipers.

Step 3: Determine the Retracted Length of the Cylinder

Identify the retracted length of the cylinder, which is the distance between the centers of its pin holes when fully closed, by using a tape measure.

Step 4: Measure the Extended Length of the Cylinder

Measure the extended length of the hydraulic cylinder, which is the distance between its pin holes when fully opened, using a tape measure.

Step 5: Calculate the Stroke Length

Calculate the stroke length of the cylinder by subtracting the retracted length from the extended length. For instance, if the retracted length is 12 inches and the extended length is 34 inches, the stroke length would be 22 inches.

Step 6: Conduct a Thorough Visual Inspection of the Hydraulic Cylinder

Perform a detailed examination of the cylinder's hose ports, which are used to connect hydraulic lines for fluid delivery. Look for any signs of unusual wear and tear, and replace any accessories as needed.

INDICATIONS OF MECHANICAL MALFUNCTION

In the event of unforeseen mechanical failure, it is imperative to utilize hydraulic cylinder seal kits. Identifying signs of seal failure may include visible oil leakage around the cylinder, alongside more complex indications.

A decrease in hydraulic pressure, cylinder overheating, loud disruptive noises, and excessive shaking and vibration are all red flags that necessitate a thorough examination of the cylinder apparatus. Additional potential indicators of seal failure encompass: 

- Excessive Wear: Inadequate or incorrect lubrication can result in noticeable wear and tear, ultimately leading to the deterioration and discoloration of the seal.
- Seal Hardening: Hydraulic cylinders subjected to high-temperature environments may experience seal hardening, culminating in cracks, tears, and rips.
- Improper Installation: A common pitfall during seal replacement is the incorrect measurement of the seal, rather than the groove in which it is situated. Utilizing an improperly sized seal can result in oil leaks, contamination, or decreased pressure, adversely impacting the cylinder's functionality.

- Contamination: Accumulation of foreign matter such as dirt, debris, sludge, and mud within the cylinder and seal can escalate if left unaddressed, eventually reaching the piston and impeding the cylinder's operation.
- Seal Fracture: Abrupt impacts, shocks, or utilization of substandard seals can lead to fracturing, tearing, or ripping of the seal.