New Design Features:
• Interior Design – more efficient flow and operation
• Dual Locking Nuts – vibration resistant for setting maximum pressures
• New Spring Material – more resistant to fatigue, powder paint resists rusting
• Piston – large diameter, more strength and contact area for shifting alignment
• Discharge Nipple – sealing o-ring has been moved to the lower part of the thread, increases hydro strength and fitting strength
• Shutter Valve – hex design, less contact area for smooth shifting (prevents binding). larger size, longer life and more positive shifting

Featuring:
• Integral switch detects full bypass mode
• Use for burner control or time delay switch
• Over sized handle – easier adjustment
• Forged valve body – excellent strength
• Two by-pass ports
• Ultra thick inlet and discharge ports - added strength
• Color coded springs and caps – easy valve identification
• All ports are FNPT

Specifications:
• Spring Color: Black
• Replaces AL687 & MV550MS
• Maximum Pressure: 4,500 PSI
• Max. Volume: 8.0 GPM
• Micro Switch 6 AMP, 250 V
• Adjustable pressure
• Brass valve body
• Max. Fluid Temp.: 194° F.
• Inlet Port (1): 3/8" FNPT
• Discharge Ports (1): 3/8” FNPT
• Bypass Ports (2): 3/8” FNPT
• Weight: 33.3 oz

Features
• Made in Italy with high quality materials
• Fits General Pump Models: CW2004, CW2040, CW3040, T1011, T1321, T1505EBF, T1621, T2031, T721, T731, T9051EBF, T921, T9211, T9281, T9721, T9731, T9791, T991, T9951, T9971, TS1011, TS1021, TS1321, TS1511, TS1621, TS1711, TS1811, TS2011, TS2021, TT2028, TT2035, TT9061, ,TS9071, TT9111, TT9351, TT941, TT9441

Kit Contents
• 6 Check valves
• 6 O-Rings, check valve