Key Terms
This is the term for systems that use water as the medium to transfer heating or cooling energy throughout a building.
What is hydronic(s)
This pump component creates the pressure differential that drives water through a hydronic system.
What is an impeller?
This pump accessory combines an elbow, straight pipe section, and strainer into a single body while conditioning flow into the pump inlet.
What is a suction diffuser?
This tank uses an internal bladder to absorb water volume expansion as the system heats up, helping keep system pressure stable.
What is a diaphragm (bladder) expansion tank?
In the bid-and-spec construction market, all project money ultimately comes from this party, who sets the budget and carries the project’s financial and contractual risk.
Who is the owner?
This is the unit of thermal energy capacity found on every boiler and chiller nameplate.
What is a BTU (British Thermal Unit)?
In a primary–secondary hydronic piping arrangement, the system typically uses this many separate sets of pumps: one for the primary loop and one for the secondary loop.
What are two sets of pumps?
In this pump style, fluid enters axially and discharges at a 90-degree angle to the suction connection.
What is a base mounted end-suction pump (FI series)?
In a closed hydronic loop, the expansion tank is typically installed at the circulator’s point of no pressure change, on the suction side of the pump.
What is the suction (inlet) side of the pump (point of no pressure change)?
In a bid-and-spec project, this party produces the plans and specifications, focusing on design intent and code compliance rather than construction means and methods.
Who is the consulting engineer (mechanical design engineer/architect)?
In this type of piping loop, water circulates under pressure with no exposure to the atmosphere or open air.
What is a closed loop (closed hydronic system)?
This damaging phenomenon occurs when vapor bubbles form and violently collapse inside a pump, eroding the impeller over time.
What is cavitation?
Installed at the pump suction and discharge, this flexible connector absorbs vibration and reduces noise, mechanically isolating the pump from the piping system.
What is a flexible connector (pump connector)?
The Taco 4900 series removes these two things from the hydronic loop in a single coalescing separator.
What is air and particulate dirt?
When selecting HVAC equipment in the bid-and-spec market, the mechanical contractor is usually most focused on these two factors.
What are cost and lead time?
This type of piping loop is open to the atmosphere, as seen in cooling tower basins and other evaporative systems.
What is an open loop (open hydronic system)?
On a pump curve, this is the maximum head a pump can generate, occurring at zero flow.
What is shutoff head?
The Taco MPV combines these three valve functions into a single body on the pump discharge.
What are vertical in-line pumps?
The makeup water assembly performs these two core functions for a hydronic loop.
What are initial system fill, maintaining system pressure, isolation from city water supply?
Hoffman & Hoffman is this type of HVAC company, acting as a bridge between top equipment manufacturers and the needs of contractors and owners.
What is a manufacturers’ representative (HVAC rep firm)?
This unit of pressure is expressed as the equivalent height of a water column, where 1 PSI equals 2.31 of them.
What is feet of head (ft. H₂O)?
o prevent cavitation, the Net Positive Suction Head Available (NPSHa) must always be this compared to the Net Positive Suction Head Required (NPSHr).
What is greater than (higher than)?
On the pump discharge, the Multipurpose valve (MPV) combines these three core valve functions into a single body.
What is shutoff, check, and balancing?
On the pump discharge, the multipurpose valve combines these three core valve functions into a single body in a hydronic loop.
What are shutoff, check, and balancing?