Focus on Harsh Environments: Valve Values

Five years ago, the management at Vulcan Chemicals, a business group of Vulcan Materials Company, commissioned a study to identify components representing high annual maintenance costs. The outcome: instead of expected high-ticket items like heat exchangers and pumps gobbling up dollars, it was determined that valves and piping represented up to 80% of the maintenance budget’s allocations in certain cost centres.

The study indicated annual potential savings of up to $500,000 in valve replacement costs alone if a program could be developed to guide purchasing and improve maintenance procedures.

A valve team was established to develop the program. It was clear to the valve team that documented information would be essential in order to work with suppliers whose products handle Vulcan’s wide range of industrial and specialty chemicals. Hard data would counter (or support) suppliers’ claims on their product performance vs. their competitors’ product performance. Data also would provide Vulcan with the information needed so it could ask the right questions of suppliers. More importantly, it could be used by Vulcan and its suppliers to guide improvements leading to the design and delivery of a better product.

Today, becoming a preferred supplier at Vulcan means delivering valves that pass a two-year in-line test program without failure. During the test program, valves are inspected daily by Vulcan personnel. Vendors must contact Vulcan every three months for a status report–unless a problem occurs, in which case Vulcan contacts the vendor. If a failure occurs during the period, it does not automatically disqualify suppliers, but they must co-operate in a failure analysis to determine the root cause and corrective action.

Vulcan and companies like it use a variety of valve configurations to handle various processes. A substantial portion of this inventory is represented by diaphragm valves to handle products such as 33% hydrochloric acid (HC1).

In one instance, 3-in. diaphragm valves installed to handle HC1 started to leak. Vulcan traced the problem to seasonal changes in temperature and differing coefficients of expansion between the valve body components. The problem was isolated without the co-operation of the vendor, who declined to co-operate with Vulcan in a joint effort to improve the product.

ITT Engineered Valves responded to a request for a proposal that included an agreement to fully participate in the two-year, in-line test program using its Dia-Flo diaphragm valves. Proper alloy specification solved the leaking problem. In addition, the monitoring program disclosed another opportunity to improve the product’s performance in the highly corrosive HC1 environment by upgrading the alloy content of the bolts.

Ilene Brett, product manager for the diaphragm valve line at VVF Engineered Valves, notes that the monitoring program “saved Vulcan tremendous amounts of money, not just in material costs, but in downtime, lost production and labour.” The Vulcan monitoring program also creates a stronger technical relationship between the customer and supplier. Brett adds that Vulcan’s input was very helpful in designing the Dia-Flo solid plastic diaphragm valve line.

To date, cost savings attributed to the improved performance of the new valves have amounted to $200,000, excluding savings attributed to reduced plant downtime and product loss.