A critical valve may be defined as a valve that, upon failure, jeopardizes a company’s operations (read as profits). Price and availability are normally key factors when making a determination to inventory valve spare parts or replacement valves.
A finance or inventory control manager may say that a valve is not critical if it is a significant capital investment while someone in production is more concerned about the functionality, the safety of their personnel and the time and monetary loss of production if the valve were to fail. Every facility has a different tolerance for how much capital they want to tie up in inventory that is not directly supplying them with output (money). Here are a few factors to consider when determining your stock of critical spare valves since it is imperative to re-evaluate your stock periodically to determine, based on market pressure, whether your critical spares plan is still effective and viable.
There should be an analysis done on whether it is more economical to stock a complete valve vs. repair parts for the existing valve. Typically, on large bore valves, repair kits are the best way to go. We always recommend that plants purchase inline repairable valves for all applications, whenever and wherever possible. We find that when a plant is built they are using less expensive non-repairable valves to keep the build cost down. With staffing levels a challenge for everyone, most customers need to rely on outsourcing valve installation, which becomes another hurdle if a valve should fail. Remember, as soon as a valve starts leaking it is damaging the valve seats, if this is allowed to continue you may get to the point where the valve is non-repairable and a new valve will be your only option.
Safety
Plant safety is the most obvious. Valves that directly relate to keeping your plant and your personnel free from potential harm are CRITICAL. These valves consist of isolation valves, safety relief valves, pressure reducing valves, emergency shutdown, and emergency vent valves (really any valve that has the name “emergency” before it should have a spare). Not having a valve or repair parts on hand could lead to injury of personnel or even worse - a catastrophic accident.
Production
Valves that directly relate to the efficiency and reliability of producing your product are also CRITICAL. It is understandable to think that all the valves in your system work alongside each other and are thus a part of the entire system, but the valves that are large, seeing high temperature and/or pressure or have custom components (special trim) will be valves that are not readily available off the shelf. You need to take an inventory of those valves and know where you can get one in a moment’s notice or have one on hand to avoid costly downtime at your facility. Consider what the valve costs compared to the potential lost revenue and production, as well as having to pay staff that does not have a production line to work on.
Lead Times
The valve industry has always had long lead times where standard non-stock lead times would be to receive a valve within 10-12 weeks. Today, you would be VERY lucky to get that type of turnaround on a non-stock valve. With the world still recovering from pent up demand after the lockdowns of 2020 many valve manufacturers are promising lead times as long as 26 to 52 weeks for their non-stock valves. This can include large quarter turn valves, control valves, safety relief valves and high pressure forged and cast steel valves. What to consider is how CRITICAL is that valve to your operation? Could you operate the plant without that line? What will it take to get that line back up and running? Could you do a quick repair on that valve while you wait for the new valve to come in or is in irreparable? When speaking with your finance department they need to weigh the risk vs. the initial lower investment of the valve sitting on the shelf since their decision could cause weeks of lost or inefficient plant operation.
Obsolete or non-supported valves
Welcome to 2021. In certain cases, the valves you have in your plant may have become obsolete because of design changes or consolidation of valve designs due to the sale of manufacturers. While some valve manufactures truly control their designs regardless of the country they are using for production, others might have a substantially different design for the valves they produce in China versus valves they produce in India. To complicate matters further, some valve manufacturers have sold operations to other companies, including direct competitors. In the case of a valve company buying the rights to another valve manufacturer, there are cases of the acquired valve line continuing to produce valves under their former name and model number, but using an entirely different design.
The XYZ model 1234 may now have an entirely different casting, alternative materials and design, different Cv and end-to-end dimensions, etc. You may also run into valves that were manufactured overseas and now have no distribution or presence in the USA.
In these cases you would want a qualified valve distributor to recommend a replacement, so that you are prepared if that critical valve should ever fail.
Solutions
Repair
We understand that you cannot have a direct replacement for every valve in your plant. However, there are ways to save on time and money while still having a critical spare on hand. The next time you deem that one of your valves needs replacing do not be so quick to discard the old one. The larger the valve the more it may benefit you to have a reputable repair company repair the old valve so that you can keep it as a spare for the next time it’s needed.
Product Standardization
In the case of larger companies with multiple plant locations, the importance of product standardization on a company’s critical spares throughout all of a company’s locations is a very intelligent standard operating procedure. When engineering agrees on certain types or brands of equipment/parts it makes a whole lot of sense to keep one critical spare at a central plant for immediate shipment to wherever/whenever it is needed, thereby minimizing the monies tied up in this area.
Consignment
Do you have a solid with an established local distributor? If yes, then consignment of certain critical valves may be an option for you. With a commitment to buy the valve when needed, the “right” distributor will store the valve in their warehouse for you until you need it. This allows the distributor to stock the valve for other customers but to also always have one on hand for you. If you do not have this type of partnership relationship with a local distributor, please call Collins and we can and will be that partner for you!