The Flow Blog

Whether you're a wholesaler, a new technician, or someone supporting contractors in the field, knowing the full lifecycle of a water system — from drilling through distribution — is essential. The Water Systems Handbook (Book I–IV) outlines the full construction of a sanitary, high-performing well system, while the Merrill Catalog provides the specific components used at each stage. This guide gives your team a clear, technical, manufacturer-approved overview of how a water system works and where each Merrill component fits in. 1. Stage One: Drilling & Well Construction Where groundwater access begins. The Water Systems Handbook explains that proper well construction includes: Drilling to an aquifer appropriate for long-term adequate yield Setting casing to isolate the well from contaminated shallow layers Sealing the annular space with grout to prevent surface water infiltration(Book I, Well Construction) A sanitary well requires: ✔ Casing termination above ground The Handbook requires wells to be completed above finished grade to avoid contamination from surface water. ✔ A sanitary well cap or well seal A critical protection to prevent insects, debris, and vermin infiltration. ✔ A proper vent Vents must be screened to allow pressure equalization while keeping out contaminants. Merrill components used at this stage (Catalog pp. 80-85): Well caps Sanitary caps Well seals All provide casing-size charts and specifications.Merrill2026 Your browser does not support the video tag. Sanitary well caps and seals help protect the well opening from insects, debris, and surface contamination. 2. Stage Two: Submersible Pump Installation How water is lifted from the aquifer. According to the Handbook, submersible pumps are installed deep in the well and connected by drop pipe, wire, and a discharge assembly (Book II, Pump Installation).Water Systems Handbook 13th Edition Key system components: ✔ Drop pipe Transmits water from the pump to the surface. ✔ Pump cable & splice kit Provides power while maintaining waterproof electrical connection. ✔ Safety rope  Provides extra safety if pipe fails and supports pump weight during lowering and servicing. ✔ Check valves Prevent backflow, pressure loss, and water hammer. The Handbook and Merrill catalog align on the need for multiple check valves in deep wells. Merrill components (Catalog pp. 151–163): Several material options available in check valves No-lead check valves Variable Flow Check Valve Stainless steel options and specialty valves Check valves and pump accessories help protect the submersible pump system and keep water moving in the right direction. 3. Stage Three: Pitless Discharge & Sanitary Sealing The transition between underground and the pressure system. The Water Systems Handbook defines pitless units and adapters as components that: Provide a watertight, frost-proof connection Prevent contaminants from entering near-surface openings Allow full service of submersible equipment without or limited excavation(Book IV: Components) Merrill Pitless Units (Catalog pp. 42-79): Factory pressure-tested ASSE/PAS-certified watertight design Positive mechanical seal with stainless adjusting nut Stainless steel on all parts touching water Full diameter access inside well These ensure long-term sanitary integrity and easy well maintenance. SPP Pitless Units help create a watertight, frost-proof connection between the well and the underground discharge line. 4. Stage Four: Distribution to the Pressure System Where water leaves the well and enters the home or facility. This stage includes: ✔ Pressure tank Maintains constant water pressure and reduces pump cycling.(Book VIII, Pressure Tanks – Handbook) ✔ Pressure switch Controls pump on/off operation based on waterline pressure. ✔ Relief valve Protects the system from dangerous overpressure. ✔ Tank tees & fittings Connects tank, switch, gauge, drain valve, and relief valve. Merrill manufactures essential fittings that appear throughout this part of the system. Your browser does not support the video tag. Heavy-duty pressure switch features help control pump operation based on system pressure. 5. Stage Five: Yard Hydrants & Outside Water Distribution How water is delivered outdoors. The Water Systems Handbook describes hydrants as surface-accessible delivery points requiring frost protection and proper drainage. Merrill hydrants — AnyFlow, Hide-Drant, C-1000, M-2000, R-6000, E-5000, and several more — use a drain-back design where: The valve body is buried below frost line, Water drains into the ground or a clean gravel bed after shutoff. Correct installation prevents freeze failures, back-siphonage, and contamination risks. AnyFlow hydrants use a drain-back design to help protect water access from freezing after shutoff. 6. Stage Six: Inside Distribution & Final Use How water moves inside the building. Components include: Shutoff valves Manifold fittings Well faucets Hose bibbs Indoor water distribution fittings While Merrill is known primarily for external well system components, many of its parts (e.g., NL fittings, valves, adapters) integrate into indoor systems depending on the application. 7. Understanding the System as a Whole (Why This Matters for Wholesalers & New Techs) The Water Systems Handbook stresses that every well is a complete sanitary system, not a collection of random parts. A wholesaler or technician who understands the entire path: aquifer → pump → pitless → pressure tank → distribution → hydrant can: Recommend the right components Reduce contractor callbacks Help diagnose system failures Increase system longevity Ensure sanitary compliance Improve customer trust And because Merrill covers nearly every stage with certified components, technicians can build a compatible, long-lasting reputation using one supplier. 8. Where Merrill Components Fit in the Full System (Catalog-Verified) System Stage Merrill Component Catalog Pages Wellhead Well caps, seals, vents 80–85 Submersible pump Check valves 151–163 Frost protection Pitless units, adapters 42–79 Yard distribution Frost-proof hydrants 8–41 Above-ground and below-ground plumbing Fittings, valves, accessories See index All page references are directly verifiable in the 2026 Catalog. You can click Here: Merrill2026 Final Takeaway Wholesalers and new technicians don’t just sell components — they support an entire sanitary water system. When you understand: How wells are drilled How pumps are installed How pitless units protect sanitation How pressure tanks assist flow How hydrants deliver water How fittings ensure system integrity …you become a trusted partner to contractors, drillers, and homeowners. And with Merrill’s catalog covering nearly every stage from drilling to distribution, your team can confidently recommend reliable, certified, American-engineered components backed by 77 years of industry experience.