Jiangsu Haifa Machinery Manufacturing Co., Ltd.

In the delayed coking unit of a Russian mixed cracking project, the high-pressure coke-cutting water pump is a critical piece of equipment within the hydraulic coke removal system. It is not an ordinary clean water pump, nor a general process circulation pump; rather, it must deliver coke-cutting water steadily to the top of the coke drum in a short time, forming a high-pressure water jet through the drill pipe and coke cutter to cut, wash down, and discharge the coke layer inside the drum. The direct impression Haifa Technology has is: the real test for the coke-cutting water pump in a delayed coking unit is not a single parameter like flow rate or head, but rather high pressure, multistage design, wear resistance from erosion, frequent start-stop cycles, pressure fluctuations, impact loads, and long-term operational reliability.

For this project, we adopted the API610 BB5 double-casing high-pressure multistage centrifugal pump. The BB5 pump's outer casing has strong pressure-bearing capacity, and the inner core uses a BB3 direct pull-out core structure, which facilitates shorter maintenance times and is suitable for high-pressure conditions such as oil refining, coking, hydrogenation, high-pressure water decoking, and boiler feed water. For a Russian refinery project, the equipment must not only meet process parameters but also the low-temperature environment, on-site maintenance habits, spare part interchangeability, and the stability requirements of continuous production units.

1. Why Choose the BB5 High-Pressure-Cutting Water Pump for Delayed Coking Units

During the operation of a delayed coking unit, a hard coke layer forms inside the coke drum. During decoking, the system needs to use high-pressure water to complete two actions: drilling and cutting. If the coke-cutting water pressure is insufficient, the coke layer is not cut cleanly; if the flow rate fluctuates significantly, the coke cutter operates unstably; if the pump set vibrates heavily, the mechanical seal, bearings, and coupling are all affected. During the selection process, we focused on four key issues:

First, whether the pump's head is sufficient. The coke-cutting water pump needs to deliver water to the high-position coke drum, and then through pipelines, valves, rotary joints, drill pipes, and the coke cutter. The system resistance is high, so sufficient pressure margin must be reserved.

Second, whether the pump's flow rate is stable. Hydraulic decoking is not a continuous, steady low-flow condition but involves obvious switching and impact processes. The pump curve should not be too steep nor should it operate in the low-flow zone for periods.

Third, whether rotor structure is reliable. The BB5 multistage pump has many impeller stages and a long rotor. Axial force, radial force, and critical speed must be controlled to avoid vibration amplification after long-term on-site operation.

Fourth, whether maintenance is convenient. Russian project sites typically pay more attention to spare lead times and maintenance efficiency. Therefore, we adopted a pull-out core design to allow inspection of internal rotor components without major disassembly of the inlet and outlet main pipelines.

2. Technical Configuration of Jiangsu Haifa BB5 High-Pressure Coke-Cutting Water Pump

For the delayed coking unit of this Russian mixed cracking project, our high-pressure coke-cutting water pump is designed according to the API610 standard. Based on the on-site technical parameters, our company's key configuration is as follows:

| Project Item | Technical Configuration |
| :--- | :--- |
| Pump Type | API610 BB5 Double-Casing High-Pressure Multage Centrifugal Pump |
| Application Location | Hydraulic Coke Removal System of Delayed Coking Unit |
| Medium Conveyed | Coke-Cutting Water / High-Pressure Decoking Water |
| Typical Flow Range | 250 m³/h |
| Typical Head Range | 0 m |
| Design Pressure | 10～45 MPa |
| Applicable Temperature | Ambient to 115°C |
| Structure Type | Double Casing, Radial Split, Outer Barrel, Multistage BB3 Pull-Out Core |
| Impeller Type | Multistage Closed Impeller |
| Axial Force Balance | Balance Drum / Balance Disc / Combined Balance Structure |
| Bearing Configuration | Sleeve Bearings or Rolling Bearings, selected based on power and speed |
Lubrication Method | Bath, Oil Ring, Forced Lubrication, or Oil Mist Lubrication |
| Seal Scheme | API682 Mechanical Seal, Plan 32 |
| Drive Method | Direct Motor Coupling, Fluid Coupling, Gearbox |
| Material Selection | C-6 |

One point to clarify here: although coke-cutting water looks like water, the operating conditions are not. The water may contain fine coke powder, suspended solids, or residues from circulating water treatment. Under high pressure, this affects the impeller, wear rings, balance mechanism, and seal flush. Therefore, in this project, we not treat it as an ordinary clean water pump but as a critical pump for high-pressure refining units. The flow components, such as the impeller, underwent heat treatment to enhance wear resistance.

3. Key Issues We Addressed During Project Selection3.1 Rotor Under High HeadThe core of the BB5 high-pressure multistage pump lies in the rotor. The more stages, the higher the head, and the more critical rotor stability becomes. During the design phase, calculated the inter-stage pressure, axial force balance, bearing span, and critical speed to avoid resonance risks near the rated speed.32 Pressure Fluctuations During the Coke-Cutting ProcessDuring hydraulic decoking, the system pressure changes when the coke cutter switches from drilling to cutting. In the pump curve design, we aimed to keep the operating range stable, avoiding prolonged operation in excessively low or high flow zones. For projects requiring frequent adjustments, variable frequency motors or fluid couplings can be used to make the pump set more adaptable to on-site operations.3.3 Mechanical Seal ReliabilityThe seal of a high-pressure coke-cutting water pump must consider not only static pressure but also start-stop impacts, pipeline vibrations, and water quality conditions. We selected the API682 mechanical seal scheme based on on-site water quality and pressure levels, and made provisions for seal flush, cooling, and pressure monitoring. The purpose is simple: reduce dry friction on the seal, minimize leakage points, and extend the continuous operation cycle.3.4 Maintenance Convenience at Russian SitesRussian refinery projects are often located in remote areas with long spare part lead times and on-site maintenance conditions may not be as convenient as in domestic factories. Therefore, in the pump set design, we maximized the proportion of common parts. Wear parts such as bearings, seals, wear rings, and balance sleeves are handled with a mindset of replaceability, traceability, and pre-stocking.4. From Manufacturing to Operation, We Focus on Long-Term StabilityDuring the manufacturing of this BB5 high-pressure coke-cutting water pump, we focused on several key aspects: non-destructive testing of pressure-bearing pump body parts, dynamic balancing of the impeller and rotor, core assembly clearances, seal chamber dimensions, bearing housing machining accuracy, and vibration, temperature rise, and performance curves during the full-load test.

For API610 chemical process pumps, factory acceptance test is not a formality. Especially for BB5 high-pressure pumps, flow rate, head, efficiency, shaft power, vibration values, and bearing temperature rise must all be confirmed item by item. Only when the clean water test curve is stable can the on-site coke-cutting water conditions be based on it. After the project was put into operation, this pump operated stably in the hydraulic coke removal system of Russian delayed coking unit, meeting the requirements for high-pressure coke-cutting water supply. For us, this was just an ordinary supply but a practical validation of the Jiangsu Haifa API610 BB5 high-pressure pump in an overseas refining unit.

5. Technical Insights from This Project

Through this Russian mixed cracking project, I am more certain of one point: a high-pressure coke-cutting water pump cannot be selected simply based on "flow rate + head." It must be comprehensively considered in conjunction with the decoking cycle of the delayed coking unit, the height of the coke drum, the nozzle parameters of the coke cutter, pipeline resistance, start-stop frequency, water quality conditions, and on-site control methods.

Jiangsu Haifa Machinery Manufacturing Co., Ltd. has long accumulated technical expertise around API610 chemical process pumps, products covering OH, BB, VS, and other series. For conditions involving high pressure, temperature, high viscosity, flammability, explosiveness, corrosiveness, or impact loads, we prefer to thoroughly calculate the issues upfront rather than remedying them after on-site operation.

In subsequent projects in Russia, Kazakhstan, and domestic refineries, the BB5 high-pressure coke-cutting water pump, hydraulic decoking pump, and delayed coking unit high-pressure water pump will continue to be key product directions for us. For a refinery, a stable coke-cutting water pump affects not only decoking efficiency but also directly impacts the coke drum switching cycle, unit on-stream rate, and maintenance costs.

【FAQ Frequently Asked Questions】1. Why is the API610 BB5 pump suitable for the coke-cutting water pump in a delayed coking unit?Because the coke-cutting water pump typically requires high head, high pressure, and strong operational stability. The API610 BB5-casing high-pressure multistage pump has pressure-bearing capacity, making it suitable for high-pressure hydraulic coke removal systems in refining units. For projects with tall coke drums, long pipelines, and high nozzle pressure requirements, the BB5 is more suitable than ordinary single-stage pumps.2. What are the most important parameters when selecting a high-pressure coke-cutting water pump?You cannot only look at flow rate and head; you must also simultaneously confirm discharge pressure, coke drum height, nozzle pressure, pipeline resistance, water quality, start-stop frequency, NPSHa, shaft power, seal scheme, and control method. During selection, Jiangsu Haifa calculates the pump curve, shaft power, axial force balance, and mechanical seal flush scheme based on actual unit parameters to ensure long-term stable operation of the pump set.