Diamond LOK-21 Assembly Information Proper assembly of a Diamond LOK-21 is much like that of conventional bell-and-spigot PVC pressure pipe. Proper assembly of the joint requires: A clean bell and spigot, Application of the manufacturer s recommended lubricant, Maintenance of straight alignment during assembly, And inserting the spigot the correct distance into the bell. Clean As with conventional bell-andspigot pipe, the gasket and the groove area behind it should be wiped clean. If mud, dirt, silt, or other foreign material is in the sealing area, it may prevent the gasket from sealing against the spigot. In addition to cleaning the gasket area, the restraint hardware also needs to be clean. Debris in this area may prevent the hardware from engaging and keep the restraint mechanism from activating. Illustration 1. Sand shown above must be cleaned from the Diamond LOK-21 restraint hardware and gasket. Dirty hardware may prevent the restraint mechanism from working and may cause the gasket to leak. Page 1
Diamond LOK-21 is easier to install than other options for restraining PVC pipe. To make an easy installation even simpler, the product comes supplied with end plugs. The end plugs make it easier to keep the bell, gasket area, and restraint hardware clean. The plugs should be left in place as long as possible. Remove them just prior to assembling the joint. Illustration 2. The end plugs in this Diamond LOK-21 pipe help to keep dirt and other foreign matter out of the bell prior to assembly. Lubricate Lubing the Diamond LOK-21 joint is no different than that of conventional PVC pressure pipe. Clean any dirt or foreign matter from the gasket and spigot. A thin, even, uniform application of gasket lubrication must be applied to the bevel and spigot as well as the contact surface of the gasket. Gasket lubricant that is NSF certified for potable water is provided with direct shipments or can be purchased from the local distributer. Illustration 3. Applying lubricant to the pipe spigot Page 2
Align Straight alignment is a key element for an easy assembly. Misaligned pipe greatly increases the assembly force required to make the joint. This is especially true for Diamond LOK-21 restrained joint pipe due to the hardware in the bell of the pipe. Straight alignment is a must. When properly aligned, the pipe joints in sizes up to 12 can be assembled manually using a pry bar. Assemble Illustration 4. Diamond Lok-21 TM Joint assembly PVC pipe is easy to assemble correctly. Just push the spigot into the bell until the end of the bell is between the two black insertion lines. The lay length is based on the first mark closest to the end of the pipe; the second mark is for the maximum insertion allowed. Do not push the spigot farther into the bell as this reduces the angular flexibility at the joint, causes unnecessary stress on the bell, and voids the warranty on the pipe. Illustration 5 Assembly has just begun. The spigot has made contact with the grip ring and gasket inside the bell. Illustration 6. Assembly continues until the end of the bell is between the two insertion lines shown in Ill5. Page 3
Prevent Over Assembly When both of the black lines go past the lip of the bell, it is called over assembled or homed. A properly assembled joint may become over assembled when subsequent joints are made (see Figure 1). The force assembling Joint B may cause further insertion of Pipe 2 into the bell of Pipe 1. This may result in the spigot in Joint A being over-inserted. When installing pipe in a ditch, the previously assembled pipes can be center loaded with embedment material. The embedment material should hold the pipe in place while the new joint is being made. In an HDD installation when the pipe is joined above ground, it may be necessary to center load Pipe 2 with a piece of equipment in order to prevent over assembly at Joint A(see Illustration 7). Alternatively, assembly tools may be used that prevent the assembly forces from moving previously installed pipe. Examples of these tools are shown in Illustration 8 and 9. Figure 1. Assembling multiple joints. Illustraction 7. The backhoe s bucket center loads the previosly installed length of pipe to keep it from moving while the new joint is being assembled. Illustration 8. This assembly tool is called the Eagle Claw and is available from Pro Pipe Solutions. Illustration 9. This assembly tool uses a chain wrapped around the bell and a lever bar to make the joint. Page 4
Inspect Diamond LOK-21 Hardware So far, the discussion has focused on the similarities of the assembly of Diamond LOK-21 restrained joint PVC pipe and conventional PVC pressure pipe. There are a few items to check that are unique to Diamond LOK-21. Checking these items prior to assembly of a Diamond LOK-21 joint will help ensure that the job goes smoothly. Illustration 10. Diamond Lok- 21 TM Retaining ring assembly. Figure 2. Grip Ring Gap Occasionally, the grip ring may need to be removed and adjusted. Illustration 10 depicts a grip ring with an excessively narrow gap (see Figure 2 for clarification). Note: The grip ring was wedged to a much smaller diameter with steel shims. The situation was greatly exaggerated to better illustrate the point. If assembly is attempted, the grip ring may become cocked inside the casing when it comes in contact with the spigot, preventing assembly. Illustration 11. Re-sizing the grip ring The grip ring should be approximately 1/8 smaller in diameter than the retainer that is part of the bell end of the pipe. This can be easily determined by shifting the ring from side to side as well as top to bottom and noting the movement. This movement allows the ring to expand when a spigot end of another pipe is inserted. If the grip ring is too loose, the grip ring should be removed from the casing. Then, the gap can be increased by manually springing the ring apart as shown in the photo. Thick gloves are recommended as the teeth on the grip ring are quite sharp. Once the gap has been increased, correctly re-install the grip ring in the retainer as described in the next paragraph. If the grip ring is too tight in the retainer it may not contact the spigot with enough force to engage the locking mechanism and prevent the joint from seperating. Page 5
A properly sized and installed grip ring will naturally want to sit at the back (A) of the retainer as shown in Illustration 12. The grip ring installed with the 1/8 smaller diameter should be able to be rotated easily inside the retainer in the bell end of the pipe by hand. Note, if the grip ring is removed, it should be re-installed such that the tapered end(b) of the grip ring matches the tapered end of the retainer. If the grip ring is installed backwards, it will not be able to be rotated easily inside the retainer. Illustration 12. Diamond LOK-21 TM Retainer and Ring Assembly Pipe Spigot end Insertion Mark Reference Guide X Insertion Marks Y Nominal Pipe Size Minimum Insertion Mark(X) Maximum Insertion Mark (Y) 4 5 ½ 6 ½ 6 6 7 8 6 ¾ 7 ¾ 10 7 ½ 8 ½ 12 8 9 16 11 ¼ 12 ¼ LOK-21 Installation Checklist The spigot, bell, gasket, gasket groove, and Diamond Lok-21 hardware are clean. The grip ring was checked to make sure it was positioned correctly in the retainer. The grip ring has a 1/8 smaller diameter than the retaining ring. Just prior to assembly, the spigot and gasket were lubricated with the correct lube. Straight alignment was maintained during assembly. Assembly stopped when the end of the bell was between the minimum and maximum insertion marks. Previously assembled pipe did not move when subsequent joints were made. Page 6