- Published on Friday, 17 July 2009 12:56
- Written by Greg Johnson
Everyone in the valve industry should be in the protection racket. No, I don’t mean dealing with cousin Vito from Jersey; I‘m talking about protecting valves after they leave the plant for shipment to the customer or while they are in storage waiting to be used. Valves that are contaminated or damaged before they are installed are a real problem that costs the industry hundreds of thousands of dollars every year to correct, either through repair or replacement.
Every valve should be adequately packaged and protected for shipment, and every valve received by the user should be well protected until it is time for installation. As far as initial shipment, most valve manufacturers do a good job of protecting their products. There are dozens of types and styles of protectors available to cover any end configuration. These end protectors serve two valuable purposes: The first is to ensure dirt and debris stay out of the bore of the valve, and the second is to keep machined surfaces underneath the valves from being damaged enroute or during installation at the job site.
If valves are not blocked in crates for shipment, they must be strapped to skids or pallets in such a way that the valves will not slide into the machined areas of adjacent valves. Even with an end protector attached, the mass of a loose valve combined with transportation vibration can result in nasty scratches on companion valves. If the scratch is on a machined surface such as a raised face, the cost to repair the valve can reach hundreds of dollars or, if alloy valves are involved, even more.
DAMAGE FROM WATER
Most end protectors are not waterproof, and a pouring rain can penetrate through virtually any small leak path past the end connector. If moisture remains in the valve for a period of time, rust will develop that can damage interior surfaces.
The biggest enemy of good valve care is the infamous lay-down yard at construction sites. It sometimes seems like, during the dark of night, mysterious demons inhabit these places and randomly remove end covers from the valves. Without this protection, the sand, gravel, weld spatter and other construction debris collects in the valve ports. Then, unprotected serrations of raised-face valves become rapidly rusted and lose their texture and geometry, sometimes requiring expensive field machining to restore integrity. Oftentimes valves will be stored horizontally with one of the flanges flat on the ground. This poor storage practice can result in moisture being trapped in the port and possibly additional mechanical damage if the valve is dragged across the gravel.
Valve stems are usually shipped lubricated. This lubrication is a magnet for dirt and sand, which will ultimately act abrasively on the stem and stem bushing. Because of this, stems should be covered with a protective wrapping, especially if any sandblasting will be performed upwind from the storage area.
If valves have been ordered in a cleaned condition for special service applications, extra care must be taken to ensure their integrity. Bagged valves should not be stored on bare pallets due to the possibility of tearing. A valve that is to be end sealed and not bagged should have desiccant appropriate for the valve’s size and for the period it will be stored. Cleaned and degreased sealed valves are especially prone to rusting because of condensation that forms inside the completely unlubricated valve.
TIPS FOR STORAGE
Of course the optimum storage solution is inside a nice dry warehouse, but that can get expensive. So in lieu of a roof and four walls, here are some tips to follow if you have to store valves outside for a long period of time:
- Make sure that the end protectors are on the valve and tightly attached.
- Do not lay valves horizontally on the ground on one flange.
- If stored flat on the ground, be sure that timbers are placed under the flange or valve body to keep it off the ground.
- If valves are to be stored outside for a year or more, a spray of WD-40 or other rust inhibitor on the ends will help eliminate possible corrosion and damage to the raised faces of flanged valves.
- If possible, the stem threads on OS&Y valves should be protected from the elements.
- Try not to store valves near an abrasive blasting area.
- If dirt and grit has entered the valve, remove it with a careful blast of compressed air before the valve is cycled or installed.
- Take extra care in storing resilient seated valves as their seating surfaces are easily damaged.