In industrial sectors such as petroleum, chemical, power and water-treatment industries, API 610-compliant industrial pumps serve as core equipment for stable production. Among them, the OH1-type pump represents the most common, versatile and cost-effective basic model, acting as the "main-workhorse general-purpose pump" for process transportation in various manufacturing plants. It can be found in the vast majority of service conditions for conventional-medium conveyance.
The pump presented at OH1 is an API 610-compliant horizontal single-stage overhung centrifugal pump with foot-mounted support. It adopts a radially split pump casing with standard end-suction and top-discharge configuration. The complete unit is horizontally installed and fixed directly on the foundation via feet at the bottom of pump casing instead of centerline support. Featuring a straightforward construction, it is the classic baseline design among industrial overhung pumps.
In terms of core structural features, the OH1 pump is uniquely identified by its single-stage overhung impeller, foot-mounted support and back-pull-out maintenance design. To put it simply, the impeller overhangs on the front end of the pump shaft without a front-mounted bearing, delivering simplified construction and low failure rates. Its most practical merit lies in the back-pull-out configuration: when overhauling core components such as the rotor assembly, mechanical seal and impeller, there is no need to disconnect process piping or relocate the pump base, which greatly cuts maintenance workload and plant downtime. Furthermore, it supports compatibility with API 682 sealing systems for flexible seal selections. A wide range of material options including carbon steel, stainless steel and duplex stainless steel are available for different process fluids, granting extensive application adaptability. Nevertheless, it carries evident structural limitations. Foot-supported construction offers limited thermal-compensation capacity. Minor stress-induced deformation may occur under thermal exposure, hence it is not suitable for severe operating conditions with ultra-high temperature or drastic temperature fluctuation.
Compared with other industrial pumps, the strengths of the OH1-type pump align closely with real-world plant requirements, which can be summarized as reliable performance, cost-efficiency, low-maintenance demand and broad compatibility. Firstly, its simple and robust structure with fewer components brings low failure frequency. Frequent routine maintenance is barely required during operation, and it imposes modest skill requirements for operators and maintenance personnel. Secondly, it features low procurement cost and short lead time. Among API-compliant industrial pumps of identical ratings, it boasts competitive manufacturing cost due to uncomplicated construction and short production cycle, making it well-suited for large-scale conventional projects. Thirdly, it delivers stable hydraulic performance with wide coverage of flow-head ranges, low operational vibration and noise, and outstanding reliability for long-term continuous service. Fourthly, it exhibits superior medium compatibility. It can handle clean fluids such as clear water and oil products, corrosive acid-alkali liquids, as well as media containing small amounts of fine solid particles, achieving exceptional general-purpose capability.
ZA, LZA, CA and ZE series are the mainstream products within the industry. These pump series strictly comply with API 610 OH1 construction standards and are standard equipment for chemical plants, refineries and power stations. ZA and LZA series are widely deployed for conventional-medium transportation in petrochemical processes. The CA series targets heavy-duty chemical applications for high-viscosity and high-density fluids, while the ZE series applies to light-duty scenarios such as water treatment and industrial circulating-water systems, covering most ordinary industrial applications.
The pump at OH1 achieves optimal performance under conditions of moderate-to-low temperature, normal pressure and steady continuous operation. Its standard applicable temperature ranges approximately from -40 ℃ to 200 ℃, with normal pressure up to 1.6 MPa, which fully satisfies regular production demands in plants. It covers extensive application scenarios: crude oil and finished oil transportation in the petroleum sector; various corrosive acid, alkali and salt solutions as well as organic chemical fluids in chemical processes; circulating water, process water and wastewater conveyance for power and water-treatment industries.
In short, for nearly all ordinary industrial fluid transportation, boosting and circulating services excluding extreme conditions of ultra-high temperature, high pressure or severe abrasion, the OH1-type pump constitutes a safe and well-justified selection. It is the most cost-effective and dependable general-purpose process pump for industrial production.