Kirby Morgan has changed to a larger lock nut, 530-110, on the sealed pull pin assembly, 505-110. The sealed pull pins will have the new larger lock nut, 530-110, starting immediately. The hole in the pull pin knob, 550-236, has already been enlarged for quite some time in anticipation of this change. In fact, the new lock nut will retrofit sealed pins shipped since about early 2004. (No change to p/n on the knob or sealed pull pin assembly).
The reason for the change of lock nut is to ensure that this part is readily available, and to allow for ease of maintenance on the pull pin. In the past, removing the lock nut was difficult. With the lock nut and knob area enlarged, you will be able to perform maintenance on the pull pin more easily.
Also, the previous lock nut, 330-320, was becoming difficult to source and was available only in limited quantities. The new lock nut is a common size and material, thus easier to purchase and readily available.
When overhauling the sealed pull pins, if it is found that the knob is the older style with the smaller area for the lock nut, it is highly recommended that a current knob with enlarged hole be purchased along with the new lock nut, 530-110. (Current knobs will accept the previous 330-320 nuts, but we strongly recommend making all sealed pull pins you are servicing or rebuilding current).
The old lock nut is still a genuine KM part, but is only intended for use on the 305-161 SuperFlow First Stage Regulator and will be found in the 325-105 First Stage Regulator Rebuild Kit.
No change in price to the Sealed Pull Pin, 505-110.
US Retail, 530-110 Lock Nut: $0.95
Please contact your local KMDSI dealer or e-mail KMDSI at email@example.com for more information.