Historically, one of the main issues that hampered the acceptance of full open valves and seats has been the problem with the puller heads to remove these seats from the pump. Traditionally, puller heads for full open seats were a complicated, three-piece device that was heavy, expensive, difficult to use, and prone to breakage. Puller heads for valve-over-valve fluid ends have always been a problem for both web seats and full open seats. On these fluid ends, to pull the suction seat, the puller head had to be inserted through the cylinder head cover in a sideways position. After insertion into the fluid end, the puller head had to be rotated ninety (90) degrees into a vertical position, and then the puller head had to be maneuvered to engage the suction seat. At this point, the puller stem had to be blindly threaded into the puller head. Recognizing this problem, Novatech developed a new puller head design, shown in the illustration to the upper right.

The new puller head has an oblong hole at the center, through which the puller stem passes. The oblong hole allows the new puller head to be rotated or cocked at an angle. The exterior of the head is also elliptical, with special sculpturing to allow the puller head to pass through the throat of the seat when rotated, as shown in the illustration to the left. The puller head is retained on the stem by a standard nut threaded onto the bottom of a standard puller stem.

When the puller head has passed through the throat of the seat, simply shaking the stem will cause the puller head to vibrate into a horizontal position so that it can engage the bottom of the seat, as shown in the illustration on the right. A standard hydraulic puller jack can then remove the seat.

Puller Head part numbers ND-8-PH, ND-7-PH, NF-7-PH, ND-6-PH and NF-6-PH use 2 inch diameter puller stems. ND-5-PH and ND-4-PH use 1˝ inch diameter puller stems. A 1˝ inch or 2 inch standard nut is used to retain the puller head at the bottom of the stem.

This new puller head design is simple to use and inexpensive. The new Novatech puller head is especially easy to use on valve-over-valve fluid ends. Additionally, the new puller head is strong, with tests showing that the puller stem will break before the puller head.

Cast-N-Place™ is a Trademark of Novatech, LLC and is protected by U. S. Patent No. 6,955,181.