FCI Aerospace Sensors Support Navy Shipboard Systems

02 Oct FCI Aerospace Sensors Support Navy Shipboard Systems

As the Navy plans to expand production of nuclear powered submarines, FCI Aerospace is well positioned to provide sensors to support the mission, given their extensive experience in both qualified Navy sensors and commercial nuclear power.

Navy Shipboard Hydraulic Systems need reliable sensors to detect insufficient oil flow. Reliable operation of shipboard hydraulic systems is vital to critical systems on Navy ships. These hydraulic systems support the control of the ship’s steering operation, weapon systems, and other key functions.

In the same way, Air Management and Environmental Cooling Systems need reliable sensors to detect insufficient air flow. Safe and reliable operation of shipboard Air Management and Environment Cooling Systems is vital to the safety of sailors that work in confined spaces on Navy ships. These air handling systems support the ventilation of battery rooms, cargo areas and sleeping quarters. Failure of air flow in these small spaces permits the build-up of unsafe CO₂ or other hazardous gas levels that endanger personnel working or sleeping in the areas. Low flow detection in air cooling systems for shipboard electronics is also vital for continued operation of radar and Intelligence, Surveillance and Reconnaisance (ISR) systems.

Low flow detection in both these key applications is a challenge due to the harsh marine environment, difficult Navy qualification requirements and low maintenance expectations found in the Navy fleet.

The Problem

• Hydraulic System operation and Air Management System operation both require highly reliable flow sensing to signal maintenance and emergency repair requirements to shipboard operations
• Oil flow switches and Air flow switches must operate in harsh, highly corrosive, marine salt water environments with low maintenance support
• US Navy shipboard components must meet stringent requirements including shock/vibration, temperature fluctuations, Electromagnetic Interference (EMI), Radio Frequency Interference (RFI) and salt fog/stray environments defined by the Navy specifications for shipboard operation
• Traditional mechanical flow switches are unreliable with high maintenance support required for continued operation
• Preferred low flow switch points are not achievable with traditional mechanical flow switches

Solution and Benefits:  FCI AS-FS Flow Switch

• No moving parts thermal dispersion technology provides maintenance free operation with negligible pressure loss
• Full Navy shipboard qualification: MIL STD-810, MIL-STD-461, ….
• National Pipe Thread (NPT) and Flange Mounting process connections available
• Stainless Steel and Monel wetted parts and enclosures resist corrosive salt water/fog exposure
• Factory Calibrated across wide range to customer’s switch point requirement
• Normally Open or Normally Closed signal alarm configurations available
• Proven shipboard high reliability: 20+ years’ maintenance free service life
• Integral and remote electronics available
• Built under ISO9001 and AS9100 Quality Certification
• Can be configured to a wide range of pipe and duct diameters, flow ranges, media, fluid operating pressures and temperatures, and environmental temperatures

FCI AS-FS Flow Switch

The AS-FS flow switch operates over a wide set-point range in liquids of 0.01 SFPS to 10 SFPS [0,003 MPS to 3 MPS] or in air from 0.25 SFPS to 1,000 SFPS [0,07 NMPS to 305 NMPS], which is factory set to the user’s specification. FCI’s thermal mass flow switches monitor mass flow directly, and do not require pressure and temperature corrections necessary with volumetric type flow sensors.

Developed from FCI’s proven, high performance aircraft qualified flow switch designs, the Model AS-FS provides a COTS-listed liquid flow switch for faster delivery lead-times at reduced cost. Highly reliable, this flow switch has features repeatability of ± 2 percent over the full signal range. Response time is 5 to 15 seconds (typical), depending on the user’s desired switch point. Designed for rugged aerospace environments, the Model AS- FS flow switch’s standard operation pressure is up to 2000 psig [138 bar(g)], with higher pressure ranges available upon request.

The flow element is designed for freezing to frying conditions: -65 °F to 350 °F [-54 °C to 175 °C] to meet the demands of high temperature and pressure service.

The wetted portion of the probe is hermetically sealed and is made of all welded Stainless Steel and optionally available in corrosion resistant Hastelloy C-276 parts or Monel wetted surfaces.

The flow element’s heavy-duty construction provides superior resistance to shipboard shock and vibration environments in both liquid and air flow applications. It is available with a flanged process mounting utilizing a standard O-ring seal, and can be provided with a variety of military electrical connectors to match specific shipboard requirements. The electronics are hermetically sealed (welded) in an integral enclosure. Power input is 19-32 VDC per MIL-STD-704.

Standard outputs include an open collector (sink) and/or a filtered, buffered op-amp (source) (<1VDC [low flow] or >17 VDC [high flow]). Electronic hysteresis is included to prevent undesired switching when flow rates are in the vicinity of the set-point.

This AS-FS meets multiple rigorous environmental and performance of industry standard specifications. They include EMI and lightning protection of the electronics to MIL-STD-461 and RTCA/DO-160, as well as full qualification to MIL-STD-810 and RTCA/DO-160. FCI’s thermal mass AS-FS flow switches are suitable for a wide range of shipboard, aircraft and rotorcraft applications. They have proven themselves for decades in environmental cooling systems, air management systems, cooling fan failure alarms, RAM air flow failure alarming, fuel tank inerting systems, and PACK and bleed air systems.

Thermal Sensing Technology

FCI flow sensors have established an unmatched record of superior performance and reliability in the toughest aerospace applications. FCI’s unique thermal dispersion technology (TDT) provides exceptional reliability and repeatability for monitoring flow rate in liquids, air and gases. The sensing element contains two thermowell-protected platinum resistance temperature detectors (RTDs). When the flow element is installed in the pipe or duct, the reference RTD measures the temperature of the surrounding fluid, while the active RTD is heated by an adjacent heater to a temperature that is warmer than the surrounding fluid. The temperature difference between the two RTDs (highest at no flow) is read. Flow cools the heated RTD and reduces the temperature difference between the active and reference RTDs.

Higher flow results in a small temperature difference and low flow produces a larger temperature difference between the RTDs. The element RTDs are connected to a bridge circuit that senses the changing temperature difference and switches the signal output when a critical flow rate is reached. This provides a repeatable flow switch point in harsh application conditions without moving parts in the switch.

About Fluid Components International LLC, a Dwyer Omega Brand

Fluid Components International LLC is a brand of Dwyer Omega, an international sensor manufacturer. It is a world leading manufacturer of built-to-specification flow, level, temperature and pressure sensors designed for mission-critical performance and reliability. Whether military or civilian fixed-wing or rotary aircraft, or military marine service, FCI has for nearly 40 years designed and manufactured qualified, flight-worthy sensor systems to meet a broad range of military and commercial applications. Visit www.FCIAerospace.com.

About JD Technologies Global, LLC

JD Technologies Global, LLC provides premium sales and marketing services to a group of high quality, complementary manufacturers of engineered services and products who serve the aerospace, military & defense, industrial and medical industries. They develop long term relationships with key customers who value the consultative style of selling and who wish to interface with sales professionals of high integrity. Their approach is to use proven consultative selling techniques. Consultative selling is a collaborative process that leads customers/prospects through an analysis of their current situation to a resulting improvement. For more information on JD Technologies Global, LLC, their products, services and their consultative selling methodology, visit www.jdtechsales.com.