Intro4u2u

Industrial gate valves are often used in harsh environments and sometimes these valves need to be repaired. The decision to repair or replace a valve usually is a result of comparing the replacement cost to the repair cost. When the repair cost exceeds 50-65% of the cost of a new valve, the decision is usually to replace the valve, unless the delivery is unacceptable.

Generally speaking, all bronze valves, except for expensive cryogenic designs, are replaced rather than repaired. Iron valves, except for the largest sizes, are also replaced rather than repaired. Steel and alloy gate valves are the most repaired types. Steel valves smaller than 12”, class 150 are usually not repaired, unless replacements are not readily available. On the other hand, high alloy gate valves as small as ½” size may be repaired because of their high cost and long lead time.

Some gate valves, such as large diameter, buttweld end and pressure-seal types are often repaired in the field. These field repairs are often difficult and pose logistical challenges, but compared to the cost of removing them from the line and shipping them to a repair facility, field repair is more economical option.

Gate valves are still the primary choice for many service applications. Their cost of manufacture to value ratio is still very high. On typical petrochemical and refining projects today, the percentage of gate valves on the requisition is about 60-70%.
Although science and technology has made tremendous leaps during the past 50 years, most gate valves are still being produced to the same basic designs developed a hundred years ago. And until someone invents a Buck Rogers laser valve with no moving parts, tens of thousands of gate valves will still be manufactured each year, in plants from South Carolina to Southeast Asia.