Novatech introduced its uniquely designed inserts to drilling valves (c. 2001) which are now known as

Cast-N-Place™. These valves have met with great success and are widely acclaimed by drilling contractors for their superior and reliable performance. Today, approximately 80% of Novatech drilling valves are manufactured with Cast-N-Place™ inserts.

The Novatech Cast-N-Place™ Valve uses a one-piece valve body; one-piece valve bodies are incredibly strong as opposed to valves with independent retainer plates. On one-piece valve bodies, the insert retention groove acts as a circular channel beam to add tremendous rigidity to the valve body. One-piece valve bodies also tend to be less expensive to manufacture than valves with independent retainer plates. In the past, traditional one-piece valve bodies have used Snap-On style valve inserts, which is the primary cause of the problem. Snap-On inserts never quite perfectly fit the insert groove because of machining tolerances, insert molding tolerances, and unpredictable heat treat warpage to the valve insert groove. As a result, the insert tends to torsionally twist in the groove with every opening and closing of the valve against the seat. This twisting in the groove actually tends to pump fluid around the backside of the insert. Eventually, a seal leak develops, and the insert washes out. This type of failure, which causes a wash to initiate between the bottom of the insert and the inside of the groove, is fairly common with Snap-On replaceable inserts. Mud debris can actually be trapped behind the backside of the insert and, in extreme cases; the trapped debris will force the insert out of the groove and off of the valve. Cast-N-Place™ inserts solve the problem of traditional Snap-On inserts by molding the insert directly on the valve body. During the casting process, the urethane insert material is poured directly around the serrations, mirroring the shape of the serrations and the valve body groove. The insert is locked in place and cannot move, leak, or be forced from the groove!

Traditional Snap-On inserts are installed by stretching the insert over the valve, which adds hoop tensile stress to the insert. On valves with screw-on retainer plates, the insert is forced onto serrations on the top of the valve body flange. The serrations cut into the insert, which weakens or adds stress to the insert. Inserts can be forced out-of-round during installation by the screw-on retainer plate or a valve with an imperfect Snap-On insert or groove.

The Cast-N-Place™ process eliminates stress by molding the insert around the serrations. Also, the Cast-N-Place™ insert is molded into a true round position on the valve that assures quick sealing with the seat.

An additional advantage of Cast-N-Place™ Insert Valves is improved service life due to induced compressive stresses in the polyurethane curing process. When inserts are manufactured, the inserts shrink by about 2% during the curing process. This shrinkage induces compressive stresses in the insert skin. Normally we think of compressive stresses as being beneficial in increasing fatigue life in steel parts under cyclic fatigue loading. Similarly, compressive stresses have advantages for inserts by increasing insert abrasion and extrusion resistance. During abrasion or extrusion, the skin is stretched a very large amount at a very localized area; in this finite small area, the urethane material is stretched greater than the tensile strength that the material allows, which leads to tearing and failure of the insert. If surface compressive stresses are present, the urethane must be stretched an even further distance before the localized area of the skin exceeds the tensile strength of the insert material. Valve life is improved and made more reliable by the benefit of the Cast-N-Place™ process.

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