Hoffer Flow Controls Turbine Flowmeters for Subsea Applications
Hoffer Flow Controls is a manufacturer of custom subsea turbine flowmeters for a variety of subsea applications, including flow-monitoring on BOPs, ROVs, hydrate remediation skids, tooling skids and more. We provide customised flow solutions for the most demanding subsea flow environments.
Subsea turbines for BOP and ROV applications
HO series subsea turbine flowmeters provide flow-measurement solutions for demanding subsea environments. Designed to operate in depths of 20,000ft or more, the HO series is a fit-for-complex application involving BOPs, ROVs, wellhead additives, subsea production systems and a variety of other subsea flow applications.
Built-to-order according to required specifications, the housing on the HO series subsea flowmeters is typically custom designed to fit into the customer’s existing footprint / space. Internally, the Subsea series is built with long-lasting durable components, meeting military standards for high-shock (MIL-S-901D) and vibration (MIL-STD-167-1).
HO series flowmeters can be designed and constructed to meet most compliance standards including API6A/17D.
Subsea turbines for tooling skids
Hoffer HO series subsea turbines for tooling skids are used to perform various testing and maintenance functions in a subsea environment. Hoffer subsea turbine flowmeters are routinely used to meter various liquids on tooling skids.
Hoffer designs and supplies fully-integrated subsea flowmeters suitable for use in all depths. Various configurations are available with a wide variety of end connections, including SAE, Grayloc, R-Con, T-Con, ANSI, NPT, MS, DIN, Autoclave, and many others. A wide range of construction materials; including, 316, 316L, Nitronic 50 and 60, Duplex 2205 and others are available. The flowmeter design includes a ‘riser’ built on the flowmeter that houses the signal conditioning module.
The need to transmit the flow signal to a remote input control device, either located underwater or on the surface aboard the production facility, requires the use of specialised electrical connectors to permit wiring interfaces. The Hoffer design incorporates a subsea connector, which is often welded to the top of special risers that enclose the meter coil.
Hoffer offers a wide variety of output signals, including RS-485, TTL/CMOS pulse, open collector pulse, and analog outputs. NIST traceable calibrations are supplied with all flowmeters. High-performance accuracies of +/-.5% per reading or better are available.
Hydrate remediation skids for subsea applications
The Hoffer Autoclave® series for hydrate remediation skids is designed to be used in the event of a hydrate plug. All operations are performed using an ROV.
In this application, Hoffer subsea flowmeters are typically used to monitor and control the flow rate of methanol or MEG. The Autoclave series of high-pressure flowmeters are ideal given the high working pressure (10,000psi) that the flowmeters will see in service. This series provides flowmeters with working pressures ranging from 10,000psi – 20,000psi, depending on the Autoclave size selected.
Wide flow rangeability is also very important for this application. Hoffer offers flowmeters that are capable of providing 100:1 flow turndown ratios. Response time is also a consideration for this application. The Hoffer Autoclave series has a response time measured in milliseconds.
The flowmeter is also lightweight and small in size. Flowmeters with Autoclave fittings are available in sizes ¼in through ¾in and provide flow-rate capability from 0625GPM through 35GPM. Subsea flowmeters for this application are also available with other suitable high-pressure fittings.
Reliability is extremely critical given the conditions the flowmeters will see in a subsea environment. Hoffer turbine flowmeters have become the preferred choice for many subsea skid manufacturers.
Conditioners, amplifiers and transmitters
The Hoffer CAT series is a compact design of flow conditioners, amplifiers, and transmitters for use in combination with Hoffer turbine flowmeters. This trio of microprocessor-based devices is capable of providing signal conditioning, amplification and transmission, depending on customers’ needs.
Several enclosure options are available, including general purpose with or without DIN rail-mount, NEMA explosion-proof and ATEX-approved explosion-proof. CE-compliant units are optionally available. The architecture of these units uses a combination of different circuit boards to create the many different options.
There are three varieties of the CAT series. The CAT1 is an intelligent loop-powered 4mA-20mA transmitter with linearisation, and the CAT2 is a signal conditioner offering a variety of output options and also optional high and low-flow rate alarms. The CAT3 is an intelligent signal conditioner with linearisation and provides a pulse output, scaled per unit of flow, and optional high and low-flow rate alarms.
Turbine flowmeters for high-pressure applications
The Hoffer HHP series turbine flowmeters for high-pressure liquid and gas applications provides the user with the ability to monitor their high-pressure flow applications, providing outstanding accuracy of +/-0.5% per reading (+/-0.25% typical) for liquids and +/-1% per reading for gases.
This series, which operates over a wide range of temperatures, uses 316L stainless-steel construction and SAE J429 grade-8 high-yield strength bolts. Pressures up to 10,000psi are available for sizes ¼in through 4in. Larger sizes and pressures are available upon request. Typical applications for this series include subsea, hydraulics and cryogenics.