Upper & Lower Kelly Valve Maintenance

Parts Assembly

  1. To reassemble, place the body with the "upper end" down. The seat with new rings should be placed snugly inside the housing (with the Teflon seal ring facing up).
  2. The operating stem (with new ring)  should be put into place in the closed position. The ball will then slide easily into the stem cog.
  3. With the seat housing "up" on the double-pin sub, install the corrugated spring and the lower seat.
  4. Lubricate the threads and shoulders (to prevent thread damage), rejoin the two body pieces, and tighten with chain tongs. Install a grease zert in the body. Use a heavy-duty, water-repellent grease and grease the valve thoroughly. Remove the grease zert and install the plug.

    The valve is now ready to be pressure-tested and placed back in service or stored for future use. When the valve is returned to the drill string, remember to make-up the two body pieces using pipe tongs or a makeup machine and the proper amount of torque for similar size API drill collar connections, or whatever is recommended by the manufacturer.

Routine Maintenance

WNCO VALVE'S kelly valves are designed with a grease fitting located opposite the stem. At least three times a week, remove the plug, install the zert and lubricate with a heavy-duty, water-repellent grease. Replace the plug before resuming operation.

TIP: Always grease the valve thoroughly and operate the stem several times after removing the valve from the drill string, even if only storing the valve for a short period of time. This will help prevent drilling mud from setting up inside the valve and "freezing" the ball and stem.

Open and close the valve two or three times a week to help keep the parts free of debris. NEVER operate the valve in a partially open or closed position; always open or close the valve fully.

Check the connections and pressure test regularly just as you would with all BOP equipment. Pressure test from the pin end as recommended by API Spec 7.

WNCO VALVE'S kelly valves are precision manufactured to provide maximum life with a minimum of maintenance. By following these routine procedures, longer and more trouble-free operation is assured.


Routine Maintenance

  • Do not tong on the stem area.
  • Grease the valve regularly, at least three times a week.
  • Use only water-repellent grease.
  • Open and close the valve often to prevent accumulations of debris.
  • Check connections and pressure test regularly.

Field Repair

  • Break the valve at the mid-body connection when removing from the drill string for repairs.
  • Remove all rings and seals and replace with new, even if they do not appear to be worn.
  • Metal parts may be reused if wear has not occurred.
  • Install parts with seals carefully to avoid seal damage (use a light coating of grease).
  • Handle threads with care.
  • Grease the valve thoroughly before placing in operation.

Quality WNCO VALVE Parts and Replacement Kits

A complete inventory of replacement parts for every model WN-2 valve is in stock at all times so there's never a delay, never a wait. You can be sure of proper fit and easy replacement in the field since all the parts are precision milled or fabricated to original equipment specifications. It is recommended that a complete parts kit be on location at all times to minimize costly downtime.

Dependable Service and Repair

There are times when the condition of a valve warrants sending it to the shop. When that happens you can depend on WNCO VALVE to provide expert repair service, regardless of the brand. From minor repairs to major overhauls, each job receives the same attention to detail found in every WNCO VALVE Product.


  1. Carefully inspect all metal parts for wear, nicks, scraper of deep abrasions, and replace if necessary. Remove all the o-rings and seals from the seats and stem, and install new WN-2 replacements.
  2. Carefully check the stem hole in the body for damage. Buff out the hole to remove any corrosion, being careful not to remove too much metal. It is important that this surface is clean and smooth before reassembly.

    NOTE: If fluid has caused any washed areas in the stem hole, if any cracks are found in the stem hole, or if the stem hole has become too oversized, the valve should not be reassembled. Instead, return the valve body to WNCO VALVE for repair. Often the body can be repaired by machining the stem hole to oversize specifications and install an appropriate oversize operating stem
  3. Clean and inspect both pins on the sub, and both boxes and the operating stem hole in the body as per standard blacklight, magnetic particle inspection. Either of the external joints (box or pin) may be reworked if there is enough space left for tong purposes after the joint is remachined. Under no circumstances should the internal box of the body be reworked; if this box is bad, the body must be replaced. On the sub, the modified pin which holds the internal seat may be reworked, but it will be necessary to remachine the seat housing as well. In this case, the sub should be returned to WNCO VALVE for precision machining of the pin and seat housing. WNCO VALVE cannot warranty machine work performed by others.

    ***WARNING If the stem hole is found cracked, even if no evidence of pressure leakage is detected, the valve body must be replaced. A crack in the stem area can severely weaken the strength of the valve body.