In a market where "cutting corners" has become the rule and not the exception, the Fisher Vertical Multistage Pump stands out in terms of engineering and reliability. Strict manufacturing practices combined with unique design features assure product consistency and maximum reliablity.
Noteworthy standard features of our seawater design include:

PUMP BOWL ASSEMBLIES
Diffusers, impellers, suction bell, and discharge case are precision cast Nickel-Aluminum-Bronze (4-1/2% nickel in accordance with ASTM B148-C95800) for superior resistance to chemical and biological corrosive attack. Impellers are positively locked to the pump-shaft with keys. All stage assemblies are flange connected and machined with male/female concentric rabbets for precise alignment. Captive o-ring seals are installed at each flanged connection to prevent leakage which can cause cutting that reduces performance, and eventually results in pump failure.

COLUMN SECTIONS
316L Stainless Steel flanges are welded to Schedule 40 seamless A106B steel pipe. Installation of captive o-ring seals at the column flange connections prevents any leakage of pressurized liquid that moves through the column string. Corrosion resistance for the steel pipe is achieved by sandblasting followed by an application, inside and outside, of 6-8 mils (dry film thickness) of Ceramkote 54. This is a new generation ceramic coating with excellent adhesion properties combined with superior corrosion/abrasion-resistance. Alternatively, two (2) coats of a Fiberglass Reinforced Polyester (FRP) resin coating can be applied. This generic coating system was ranked No. One (1) out of 29 different coating systems during a five year study conducted by the Army Corps of Engineers. Ease of touch up and repair make this system additionally attractive. The low-carbon stainless steel (316LSS) flanges require no corrosion resistant coating. Thus, typical mechanical damage encountered on contact of coated steel flanges is eliminated.

SHAFTS
Pump, head, and line shaft sections are available in several corrosion resistant materials including 316L Stainless Steel and C630 Nickel-Aluminum-Bronze

DISCHARGE HEAD
High grade carbon steel with 316L Stainless Steel column connection flanges are used in the fabrication process. Machining is performed only after welding and heat treating are completed. Steel waterway surfaces in the head are coated with Ceramkote 54 or FRP. The discharge elbow is secured to the base of the head by welded ribs, instead of a plate, which allows more complete coating of inner recesses and prevents pooling of condensation.