Replacement decision in brief
A lower bare-pump price or fewer shaft-seal repairs alone does not determine the best replacement. Compare equipment, installation, compressed-air or motor energy, maintenance, cleaning, product loss and downtime over the same project life. Use recorded costs where possible, mark assumptions, and test how the result changes with air demand and operating hours.
Build the same boundary for each option
Include equipment, installation, utilities, controls, receiving modifications and commissioning. Use the same product, throughput, operating hours and project life. A bare mechanical pump price should not be compared directly with a fully integrated pneumatic skid without identifying the missing scope.
Keep annual costs separate
List energy, planned maintenance, unplanned downtime, product loss and cleaning costs. Use plant records where available. Where an item is an assumption, mark it and explain the basis. Avoid double counting: production loss during maintenance may already be included in a downtime estimate.
Use a transparent calculation
Annual difference equals the existing system annual cost minus the proposed system annual cost. Simple payback divides additional investment by a positive annual difference. For illustration, an additional 30,000 currency units and an annual difference of 10,000 give a three-year simple payback. This excludes finance, tax and discounting and is not a SINOSEN performance promise.
Test the variables that matter
Change electricity price, operating hours, air consumption and maintenance assumptions over realistic ranges. If the decision changes after a small adjustment, gather better data before purchase. The comparison worksheet on this website deliberately uses your figures; it does not invent utility consumption or universal savings. A credible commercial case remains reviewable when a purchasing team challenges its assumptions.
General engineering guidance. Numerical examples are illustrative; project specifications and acceptance criteria are agreed for the actual duty.