The Porter with Shoulder Pole Analogy

Introduction to Basic Concepts of Gasket Deformation

We have previously covered creep, stress relaxation, as well as the creep and relaxation behaviors of flange bolted gaskets. Some of these concepts can be abstract to grasp, so this article uses the scenario of a porter carrying loads to illustrate stress relaxation and creep relaxation in plain terms.

Analogy: A Porter Carrying Shoulder Poles

 Let us set a realistic scene: A 1.75-meter-tall porter’s shoulder sits at an elevation of 1.45 meters when standing upright with no load. Once he hoists a shoulder pole loaded with 30 kilograms on each end, the total weight forces his shoulders to sink by 10 millimeters, dropping the shoulder elevation to 1.35 meters. If we ask the porter to hold this exact posture indefinitely, we can easily picture what happens in real life: even with no extra weight added, his shoulders will keep sinking slowly under constant load, and he cannot sustain the fixed shoulder height for long.

In this analogy, the porter’s shoulders stand for gaskets used in industrial equipment, while the weight of the shoulder pole corresponds to the compressive load acting on gaskets during equipment operation.

BMCSG Series: For High-Temperature Pipeline & Equipment Flanges

As a core component of flange connections, gaskets endure persistent compressive force from bolts—just as the porter bears constant weight from the loaded pole—and undergo gradual deformation over time.

BMCWSG Series: Excellent Resistance to Stress Relaxation

Grasping this intuitive analogy is the prerequisite for distinguishing creep relaxation and stress relaxation later on. With this relatable model as a foundation, researching mechanical variations of gaskets becomes far more straightforward, and we can better apply theoretical knowledge to real-world sealing service conditions.

Ingenious Seal Mastery

For sealing leakage issues, Baohua provides solutions. If you have any doubts about sealing technology, please pay attention to Suzhou Baohua and feel free to consult, comment, or leave a message!  Thank you! We will continue the discussion on the porter analogy, creep and relaxation in the next issue.See you next time!