Project- Zone Valve and Valve Actuator - For Hydronic (Hot Water) Home Heating
Zone Valve and Valve Actuator Project - While working at Honeywell's Residential Division Jeff Dayman , working with the firm's chief engineer, developed several existing product concepts to production readiness and invented many new concepts for this valve and actuator design. Design detail optimization for injection moulding was Jeff's responsibility. As many parts of the actuator and valve as possible were designed as injection moulded plastics for lowest possible cost and good function. Previous zone valves had been made by forging the centre portion of brass and soldering on machined brass end fittings of different types. After study of the tooling cost and production economics of this method, Jeff proposed a design for a family of 6 inexpensive bronze sand castings that would replace the 30 variations of forgings (and forge tooling) needed to make the family of zone valves 1/2" pipe to 1" pipe fittings size, in 2 and 3 way valves. All valves had common internal machining - the only difference between any size of two way and three way valves was the depth of the centre bore- all other machining was identical. This saved a great deal of process cost and tooling expense. The internal cartridge parts were redesigned by Jeff as modular injection moulded high heat plastic parts. A Ryton high heat plastic piston was made in two lengths for 2 and 3 way valves. A key development was special anti-blowout o-ring retaining flanges in all areas where the o-ring was disengaged from the piston during valve opening. Even with 100 psi pressure differential and huge flow rates, the o-rings would not blow out in tests with these retainers. The Ryton plastic valve cap or bonnet, exposed to full operating pressure and high temperature, was good to over 1000 psi at 90 deg C in torture testing to establish the working limits of the valves. A special triple o-ring stem seal, with a new concept lubrication system was invented by Jeff and resulted in 100,000 open/close cycle life before valve stem leakage in extreme conditions, which was about twice the life of previous valve stem seal systems in the same extreme condition test. The bayonet mounting style and casting/machining details Jeff developed allowed these valves to be the first ones offered by Honeywell where it was possible to lock a tool onto the valve body and change the cartridge under pressure, without draining the entire heating system. Draining the system is difficult and expensive in multi-storey buildings, so being able to change cartridges under pressure meant huge cost savings to building owners and maintenance staff. All mechanical detail iteration and design, CAD modeling, detail drawings, test apparatus , planning for tooling and production, tool design for some parts, and some production line development tasks for these valve and actuator products were done by Jeff Dayman under the supervision of Honeywell management and the chief engineer. The products were a major success in the market and 14 million valve and actuator sets were sold.