Month: March 2016

March 30, 2016

Marine Riser and Tensioner System Hydraulics.

While CPI’s robust linear position sensor technology works great to report absolute cylinder position under the most demanding of conditions, it also has great application as a gauge of pre-charge pressure in a hydraulic accumulator. And perhaps nowhere is the operating environment of a hydraulic accumulator more challenging than in deep sea oilfield exploration riser tensioner systems.

Marine Riser And Tensioner Systems Explained

Crews of drilling rigs understand how critical this functionality is. Without a tensioner the riser will buckle when the rig moves downward, and stretch when the rig rises. If you gather around the moon pool of any offshore rig or vessel during a storm you’ll see a riser/tensioner system hard at work. These systems use a bank of hydraulic accumulators to drive piston displacements in reaction to the heaving of a heavy sea.   It is crucial that the tensioner can manage differential movements between the riser and the rig as the riser is connected to the wellhead on the seabed. The use of hydro-pneumatics in a system comprising a hydraulic cylinder, accumulator and typically wire sheaves, enables compensation for rig movements and maintains constant wire tension.  These accumulators are constructed using a gas (typically air or nitrogen) and hydraulic fluid to drive displacements up to 12 meters.

How do CPI Linear Position Sensors Fit In?

Critical to operation of the tensioner system are accurate measurements of the air/oil compression ratio. Control systems must monitor and replace lost air dynamically and the position of the piston for a given hydraulic oil pressure is a direct indication of the need for increases to gas volume which can then be injected by an automatically controlled compressor.

CPI Linear Position Sensors like the SL-1500 and others are designed for these kinds of applications:

Hydraulic accumulator piston position sensing

CPI SL1290 Series For Hydraulic Accumulators

  • Because of our innovative draw wire design, we can easily operate for the long stroke lengths in a marine riser tensioner system. CPI sensors have operated with high accuracy to 15 meters of stroke.
  • Hardened operation is a standard feature of our design. Our sensors have no sealed cavities and are completely immune to pressure. As such, they can be mounted on the oil or gas side of the cylinder, or even outside the cylinder.
  • A patented LVDT based implementation means the core sensing technology is completely non-contacting and immune to local EMI distortions.
  • Our sensor is the only hardened sensor in the world that works with telescoping hydraulics.

Riser Disconnect Sensing and Control

Another key function provided by CPI Sensors is to provide critical feedback during a disconnect scenario. In this scenario the riser must be disconnected before the rig is critically out of position with respect to the well head.  Typically a tensioner ring employs six hydraulic accumulators with six valves controlled by the computer through signals from the valves and the CPI linear position sensor which is acting as the piston rod measuring system.  Some systems are implemented with the cylinders mounted directly to the tensioner ring as opposed to using a wireline implementation. In these systems, a riser disconnect scenario detected by the CPI linear position sensor will cause the valve to limit the oil-flow and the riser will not gain momentum as it often does in a wireline system. During disconnect the control system controls the position of the valves and the riser is brought up in a controlled way again using input from our sensors.

Contact CPI – Lets Talk Accumulators

CPI sensors are no stranger to oil field operations, and are one of the most unique offerings in the world for long stroke, piston accumulator position sensing in extreme environments.

Please call our engineering team today to discuss your hydraulic accumulator based application or visit us at http://www.cpi-nj.com.

 

This content was originally posted at https://www.cpi-nj.com/blog/marine-riser-and-tensioner-system-hydraulics/

 

March 15, 2016

The Not-So-Simple Start Switch.

Behold the simple yet much misunderstood start switch, deployed ubiquitously throughout every corner of the world, almost everywhere there is an electronic motor or actuator of some type. Simple matter of closing a couple contacts you say?  Well we beg to differ because in the world of heavy duty outdoor equipment where our products excel, there is no such thing as simple.

While start switch functionality is easy to wrap one’s brain around, a start switch’s design and manufacturing  will make the difference between imported commodity grade parts that fail in your application, and parts that will actually hold up under a high current, high endurance environment.

What Makes A Robust Start Switch?

For engineers looking for the higher quality solution to start switch part selection, there are a number of parameters that make a switch of this type both robust, and cost effective.

  1. Truly Waterproof – Outdoor applications in such industries like marine workboats, cranes and winches, work trucks, construction vehicles, generators, valve controls, etc., immunity to the surrounding hostile environment is key. And not just water, but dust, wind, sand, and pressure washing all pose a threat to the long term operation of an inferior start switch.  CPI switches like our D1040 Panel Mount Plunger Switch employ a unique seal which prevents contaminant ingress during activation and over a long life.  And they are truly waterproof, not just “water-resistant” or “splash proof”
  2. Sealed switches provide extended temperature operations. – With our proprietary sealing process our Santoprene sealed switches can operate flawlessly at both ends of the temperature spectrum, from -50F all the way to 220F without freezing up or early burn out even under heavy duty cycles. Deploying your equipment in the Artic Circle?  No problem, our Neoprene switches extend the low end further, all the way down to -65F
  3. High Electromechanical endurance. Normal CPI switches rated at 5A of resistive load can be specified with extended life features that have allowed them to achieve five million cycles of electromechanical endurance under normal operation.
  4. High Current Capabilities. CPI Manufactures switch variations that can handle up to 15A of resistive load while still maintaining endurance ratings of over 25,000 cycles.
  5. Flexible Mounting and Electrical Options – Off the shelf parts come in a wide variety of mounting and electrical configurations with configurable lead lengths.  Chances are one is right for your application without modification. We also carry switch panel mounts or you can just have us make the entire panel for you saving time and engineering headache.

The CPI Value Proposition.

If you consider the world of robust, high endurance switches, then we are without a doubt one of the most cost competitive solutions out there in production volumes. Where we make a further economic difference are all the in-warranty or mission critical repairs that you are NOT doing. Not doing because you’ve smartly specified a switch that is one of the highest performing, highest endurance designs in the world.  All designed and manufactured in the USA.

Get Started With CPI Waterproof Start Switches

If you think your application is robust enough for our start switches, give us a call and we can tell you exactly what you need, and provide you samples as required. If you need a customization, we can do that, we’ve been doing it for the military and large and small industrial manufacturers for over 70 years.

Please contact our sales team at (973) 887-9400 or visit www.cpi-nj.com for more information.

 

This content was originally posted at https://www.cpi-nj.com/blog/the-not-so-simple-start-switch/