描述
从可靠性和可维护性上看，由于电器控制系统使用了大量的机械触点，其存在机械磨损、电弧烧伤等，寿命短，系统的连线多，所以可靠性和可维护性较差。而PLC大量的开关动作由无触点的半导体电路来完成，其寿命长、可靠性高，PLC还具有自诊断功能，能查出自身的故障，随时显示给操作人员，并能动态地监视控制程序的执行情况，为现场调试和维护提供了方便。
Parker PRM3 PP17K Pressure Reducing Valve 150-2500 PSI
A810E Parker FLOCON 1-3/8″ Outlet Pressure Regulator
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PARKER/SCHRADER BELLOWS PRESSURE REGULATOR 035662000B
2683 NEW Parker 201673 Pressure Regulator
PARKER HYDRAULIC PRESSURE REDUCING VALVE V-21 FT
New Parker CPOM2AAV55X Pilot-Oper. Pressure Check Valve
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NIB PARKER BVHP16SSS1NA HIGH PRESSURE BALL VALVE
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Parker Hydr. Pressure Reducing Module D03 # BD03PNR-A
Parker 035643000B Pressure Regulator NEW Free Shipping
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Parker hydraulic cylinder model C2H19 PRESSURE 3000
Parker 3/8″ S. Air Dual Pressure Switch New
Parker Hannifin Hydraulic Pressure Control Valve 3000
Parker Pressure Switch Male DIN P01909
