Flowserve VPC Vertical Double-Case Turbine Pump (VS6)

Flowserve VPC vertical double-case turbine pump

The Flowserve VPC is a vertical turbine pump in a double-case arrangement: a mixed-flow, diffuser-style bowl assembly is installed inside an outer suction can, with the discharge head and driver at the top. It is offered in standard and in ISO 13709 / API 610 (VS6) configurations, in single or multistage form, and is designed for continuous duty, especially where the available suction head is limited.

The pump combines the hydraulics of the Flowserve VTP wet-pit vertical turbine with a pressure-containing can, so the pump can take suction from a pipeline or a vessel instead of an open sump. This page describes the VPC range as a series; the number of stages, can length, materials and sealing are set for each duty, not by a single ordering code. Seven Star LLC is an independent supplier in Muscat and quotes the VPC for Oman and the GCC.

VPC technical specifications

How the VPC double-case design works

Liquid enters through the suction nozzle of the outer can and flows down the annulus to the suction bell, which guides it into the eye of the first-stage impeller. Because the first impeller is far below the nozzle, it sees a large submergence, and the pump can run with low available suction head. The bowls contain multiple diffuser vanes that convert velocity into pressure stage by stage, and the liquid then rises through the column to the discharge head.

The manufacturer describes bowl bearings on both sides of each impeller for rigid shaft support, impellers that are enclosed or semi-open and cast for smooth passageways, and a flanged bowl construction. A rigid adjustable flanged coupling allows impeller clearance to be set accurately. With a solid-shaft motor, the motor thrust bearing carries the total hydraulic thrust and rotor weight; a separate axial thrust bearing assembly is also listed as an option.

Where the VPC fits among Flowserve pump ranges

The VPC is the pressurised-suction cousin of the VTP wet-pit turbine pump. Where a VTP hangs in an open sump, the VPC sits in a can that is connected directly to the process line, which makes it a natural fit for pipeline transportation, power generation and other low-NPSH services. For horizontal high-pressure duty the barrel pump WIK covers a different part of the market. When a mechanical seal is chosen instead of packing, the seal type is selected from the duty, pressure and temperature at the discharge head.

VPC selection and ordering checklist

• Flow, head and the number of operating points, including minimum flow
• Suction pressure, vapor pressure and available NPSH at the can inlet
• Liquid, density, viscosity, temperature range and solids or corrosion data
• Standard or API 610 VS6 build, and the edition required
• Setting depth, can length and above- or below-ground suction flange
• Impeller type, wear rings, bowl and column materials
• Sealing choice: packing, single or dual mechanical seal
• Driver: electric motor (solid or hollow shaft), engine with right-angle gear, steam turbine
• Options such as thrust bearing assembly, can drains, short-coupled or canned booster
• Site classification, painting and documentation requirements

Installation, commissioning and maintenance

A vertical can pump is installed in sections: the can goes in first, followed by the bowl assembly, column and discharge head. Verticality, alignment and concentricity of the shaft and column must be checked during assembly, and the foundation needs to carry the weight of the pump, the can contents and the dynamic loads. Grouting, vent lines and drain connections should be agreed before delivery.

At start-up, vent the can fully, confirm direction of rotation, check the impeller lift set through the adjustable coupling and observe vibration and temperature on the first run. Later maintenance focuses on bowl and line bearings, wear rings, shaft sleeves, seals or packing and the thrust bearing. Planning spares for these wearing items is cheaper than waiting for a failure, because pulling a long can pump is a larger job than servicing a horizontal pump.

Typical VPC applications in Oman and the GCC

The manufacturer lists power (including combined cycle, conventional steam and concentrated solar), chemicals and petrochemicals, mining, water management and irrigation, steel and metals, and oil and gas from upstream to downstream. In the GCC these translate into condensate and cooling services in power and desalination plants, hydrocarbon transfer in refineries and terminals, pipeline booster stations and large water supply systems.

Climate matters on the surface equipment: high ambient temperatures, dust and humid coastal air affect motor selection, seal cooling and paint systems, and should be stated on the enquiry.

VPC build and option overview

Information to send with a VPC RFQ

• Process datasheet with flow, head, suction conditions and NPSH
• Liquid data and temperature range
• Specification: standard, AWWA or API 610 VS6
• Nozzle orientation, can length and setting depth
• Driver and seal scope, and utilities available on site
• New unit, rebowl or spare part

Rebowl and spare-part enquiries should include the existing pump nameplate data.

Documents and quotation

Send the model VPC with your duty data and we will confirm which documents are available for it. Seven Star LLC is an independent supplier and does not claim any official status with the manufacturer.

We reply with a technical and commercial response for Oman and the GCC once the duty data is clear.