Control System Replacement for Stamford Hurricane Barrier, Stamford, CT

o the City of Stamford and surrounding communities. The brand-name components specified herein are manufactured by: Bosch Rexroth HYDAC Des-Case Honeywell (Sensotec) Dwyer Omega Lisle Corporation These components are required for the rehabilitation, modernization, and control integration of the existing main Hydraulic Power Units (HPUs) and hydraulic manifold assemblies. The use of these brand-name components is essential to meet the Government�s strict safety, compatibility, and performance requirements for the following reasons: The project requires direct integration with the existing HPU structures and manifolds, which were originally designed and manufactured by Rexroth. The new components must be fully compatible with the existing proprietary hydraulic flow paths, mechanical port configurations, and pressure curves. The barrier's two massive gate cylinders must operate in perfect synchronization to prevent twisting, binding, and potential catastrophic mechanical failure. The specified Bosch Rexroth proportional and counterbalance valves possess proprietary flow-gain curves and spool alignments that are essential to ensure this synchronized movement. Using any other manufacturer's valves would introduce a mismatch, inducing severe structural stress on the barrier. The existing manifolds are machined with proprietary Rexroth cavity and mounting standards. Generic commercial valves and filters will not seat properly without custom adapters, which would introduce leak paths and degrade system reliability. The specified components ensure a precise physical fit within the existing infrastructure. Schedule of Intended Brand-Name Components To afford industry full visibility to review and provide feedback, the intended schedule of brand-name components is itemized below by contract drawing schedules: HPU Replacement Parts Quantities reflect the complete project scope across both East and West Abutment HPUs (2 HPUs total). Tech Pos Description / Function Manufacturer Specified Model / Part Number Qty / HPU Total Project Qty 12 3/4" Square-Head Magnetic Trap Plug Lisle Corporation Part No. 4054121 2 4 20 Float Level Switch Assembly Bosch Rexroth Model 800PUA31-05 3 SW (Part No. R978835263) 2 4 25 Reservoir Filler Connection / Cap Bosch Rexroth Model F/ELF5-10-2.0 PUA42-11 (Part No. 97884631) 2 4 30 Desiccant Breather & Mounting Adapter Des-Case Breather DC/CS-4 & Adapter DC-12 (Part Nos. R978839894 / R978840030) 2 4 35 Temperature Switch Bosch Rexroth Model TEMP SW PUA31-30B E55-14103 (Part No. 97888127) 2 4 40 Bulbwell Steel (11.44" Long) Bosch Rexroth Model BULBWELL 11.44 LG PUA31-22 (Part No. R978802575) 2 4 43 Temperature Transducer (RTD) Dwyer Omega Model PR-12-2-100-1/4-12-E 2 4 44 Bulbwell for Temperature Transducer Dwyer Omega Model 3/4-260S-U10 2 4 45 Bimetal Thermometer Bosch Rexroth Model BIMET PUA31-14 WIKA 33X0278 (Part No. 978804856) 2 4 50 Bulbwell Steel (5.25" Long) Bosch Rexroth Model BULBWELL 5.25 LG PUA31-22 (Part No. 978804619) 2 4 75 High-Pressure Filter Assembly HYDAC Model DF BH/HC 330 T F 10 D 1.0 /-L110-B6 (Part No. 1250576) 2 4 77 Return Line Filter Assembly HYDAC Model RF BN/HC 30 B B 10 D 1.0 /-L110 (Part No. 1266488) 2 4 80 3/4" Check Valve (0.5 bar cracking) Bosch Rexroth Model S15A05-1X/420/12 4 8 85 1-1/2" Check Valve (0.5 bar cracking) Bosch Rexroth Model S30A05-1X/420/12 (Part No. R901454196) 4 8 93 Low-Pressure Gauge Assembly Bosch Rexroth Model GSA 4/400PUA31-10A (Part No. 978837831) 2 4 95 High-Pressure Gauge Assembly Bosch Rexroth Model GSA 4/3000PUA31-10A (Part No. 978837833) 2 4 110 Direct-Operated Relief Valve Bosch Rexroth Model DBDS15G1X/50-12 (Part No. 900534613) 2 4 120 Pilot-Operated Relief Valve Bosch Rexroth Model DBW15BG2-5X/315-6EW110N9K4/12 (Part No. 978917231) 2 4 Manifold Wearable Components Quantities reflect the complete project schedule for the dual-cylinder manifold assemblies. Item / Tech Pos Description / Function Manufacturer Specified Model / Part Number Manifold Schedule Qty 201.1 High-Pressure Transducer (0�2000 psi) Honeywell (Sensotec) Model Sensotec AP415DL (Part No. 60-F499-01) 6 203.1 Low-Pressure Transducer (0�500 psi) Honeywell (Sensotec) Model Sensotec AP415CR (Part No. 60-F441-01) 2 219 Directional Valve Bosch Rexroth Model 4WE6D5X/AW120-60NDA/5 (Proportional directional valve w/ OBE) 2 220 Proportional Directional Valve Bosch Rexroth Model 4WRZ16-15005X/6A24N9TD3/M-116 (Proportional directional valve w/ OBE) 2 223 Pressure Compensator Bosch Rexroth Model ZDC16P-2X/M (Part No. R900489668) 2 225 Counterbalance Valve Bosch Rexroth Model FD25KA2X/B04/12 (Part No. R900518087) 2 Salient Characteristics and Technical Rationales The use of the specified brand-name components is essential to meet the Government�s strict life-safety, mechanical synchronization, fluid cleanliness, and physical compatibility requirements. Bosch Rexroth (Hydraulic Valves, Controls, and Switches): The existing HPUs and distribution manifold blocks were originally engineered and machined to proprietary Rexroth cavity and porting standards. Replacement valves must drop directly into existing cavities without adapter plates, which introduce leak paths and structural compliance issues. The barrier gate is actuated by two massive hydraulic cylinders on opposite sides of the navigational opening. These cylinders must operate in strict displacement and velocity synchronization to prevent mechanical twisting, binding, and structural failure. Rexroth proportional (Item 220) and counterbalance valves (Item 225) possess proprietary flow-gain curves, matched spool alignments, and factory-calibrated on-board electronics (OBE) essential to maintaining synchronized motion. HYDAC (Pressure and Return Line Filtration): The close-tolerance proportional valves require hydraulic fluid (Mobil DTE 10 Excel 32) maintained strictly at ISO 4406 cleanliness rating 17/15/12. HYDAC Betamicron filter elements provide the validated single-pass Beta ratio (?10(c) ?1000) required to prevent spool erosion and sticking. The filter assemblies match existing piping brackets and incorporate integral clogging indicators (110V/B6 signal outputs) that wire directly into the PLC input modules. Des-Case (Desiccant Breathers & Adapters): In a harsh marine environment, humid and salt-laden air entering the reservoir causes rapid oil emulsification and valve corrosion. Des-Case DC/CS-4 breathers utilize high-efficiency silica gel media coupled with 3-micron particulate filtration and bi-directional internal check valves. The DC-12 quick-flange adapter interfaces directly with existing reservoir cover plates, providing a hermetic, vibration-proof seal without field drilling or hot-work near oil reservoirs. Honeywell Sensotec (Precision Pressure Transducers): The automated control system monitors real-time cylinder pressure to balance load sharing and detect hydraulic stalls. Honeywell Sensotec AP415DL and AP415CR transducers are electrically matched to the scaling tables and signal registers programmed into the PLC analog cards. Feature high-pressure flush-diaphragm threaded connections engineered to seal into existing Rexroth manifold sensor cavities without pipe-thread adapters. Dwyer Omega (Temperature Transducers / RTDs): Cold hydraulic oil degrades proportional valve response time. The Dwyer Omega PR-12E RTD temperature sensor monitors reservoir fluid temperature