If a valve is to be stored, it is important that it is properly preserved so that it functions when it is eventually installed.

Valves that are already installed must also be protected, especially during a busy construction phase with welding and grinding going on everywhere.

Here are some methods to keep you away from trouble like the one one of the oil projects faced after this unfortunate report (the image is unrelated to the report):

"According to the inspection report from the PSA, pipes were not covered at the ends, allowing sand, dust, and rainwater to collect inside them. A large number of valves, including safety-critical valves, were stored or installed without satisfactory preservation. The same applied to actuators and valve stems.
– .. valves, pipes, flanges, and other vital equipment already had visible signs of corrosion and damage. In addition, electrical junction boxes were not properly sealed and lacked silica gel, and electric motors were left uncovered and without connected heating elements. In and around the facility, sandblasting, grinding, welding, painting, and assembly work were being carried out without protection for other equipment."

In the methods below, let us assume that the preservation must also cover the construction phase. As a supplier, you might get away with simpler protection if you are delivering to a subcontractor, but the specification may just as well state that the preservation must last all the way until the platform is put into operation – if you read carefully.

External preservation of valves

The challenge is welding and grinding dust, paint, corrosion, and mechanical damage.

• Lubricate valve stems with FinLube TF and seal around them with Scapa self-amalgamating tape 2504 or 2501, so that dirt on the stem is not drawn into the packing box when the valve is operated. Continue the seal over the packing box. This simple step will significantly extend the service life.
• Grease up lubrication nipples and attach caps.
• Stainless surfaces should be wrapped in fiberglass cloth fastened with weather-resistant tape to protect against grinding dust.

Internal preservation of valves

• Clean the valves and dry them. Make sure no chemical residues, cleaning agents, or particles are left on the surface.
• Refill any gears with oil or grease so that all moving parts are well lubricated.
• Spray preservation oil, preferably oil with a VCI inhibitor, on all internal surfaces – in both open and closed positions.
• Also spray the flange faces and protect them by attaching plastic or plywood flange protectors, depending on what the specification requires.
• Lock the valves with nylon cable ties or similar, generally following the figure below.
• Store in a way that prevents the stems from bending and protects the valve from other mechanical damage.
• The specification may sometimes also require that a VCI capsule or silica gel desiccant be installed in the valve body before the flange cover is attached.

Long-term storage of valves

If you suspect the valve may be in storage for a long time before being sent for installation, it may also be smart to use VCI packaging to keep the entire valve free from corrosion. Like all plastic packaging, this should be removed when the valve is eventually installed on board.

VCI plastic is impregnated with VCI (Volatile Corrosion Inhibitor) molecules. The molecules slowly evaporate from the plastic and adhere to all metal surfaces that are wrapped inside.

The VCI vapor forms an invisible film between the metal and the surrounding atmosphere, thus stopping corrosion. This means that even if condensation forms inside the plastic, it will not cause corrosion because it is not in contact with the metal. For larger valves, it can be advantageous to also use a bag of Zerust ActivPak LS-35 inside the valve. This bag contains both VCI and FCI and is therefore very fast-acting, protecting up to one cubic meter of cargo.

VCI packaging comes in many different solutions; for this type of preservation, pallet covers are perhaps preferable. These are available in various heights to fit both full and half pallets. The pallet covers can be turned inside out, creating a bag that fits perfectly on the pallet. Tape the top securely, and everything inside the bag will remain free of corrosion for years!

To protect the valve from damage other than corrosion, such as impact damage, you must use flange protectors. We recommend Rapid Soft Cover, which consists of both hard plastic and cellular rubber for the best possible impact and dust protection. We produce these ourselves, and we can make all sizes and shapes according to drawings. The flange protectors are installed quickly and easily with the included plugs.