Mechanical seal compression amount

Do you mean by the compression amount the difference between the length before compression and the length after complete compression? Or, as I understand it, before the mechanical seal is manufactured and shipped, the allowable degree of compression is predetermined; this includes the distance required for installation in the pump as well as the tolerances involved. The pump manufacturer also has to take into account the design parameters of the mechanical seal when manufacturing the sealing chamber. This should be something you and I both understand – unless it’s a small factory that, after installation, fails to rotate the shaft properly, doesn’t carry out any adjustments, which results in difficulties in rotating the shaft and causes uneven surfaces on the stationary and rotating rings. Later on, it is only possible to rely on the workers’ skills to move the spring seat to the appropriate position; several tests, either in static or dynamic conditions, are needed to determine the unique position of the spring seat. Generally, after installing the rotating ring, a compression of 1/3 or 1/2 is sufficient; this depends on the pump’s outlet pressure as well as whether there is a single spring or multiple springs. There are too many issues related to faulty mechanical seals, which can be quite troublesome

This post was last edited by Meng Cheng from Longgang Pump Industry on 2017-3-18 at 06:18: Find the distance from the top of the shaft sleeve to the end face of the static seal ring – then subtract the height of the dynamic ring after it is compressed!

Just use a depth gauge to measure it