Application Tips

· Piping Pressure Independent Valves in Parallel for greater Flows


· Air in HVAC Systems

Griswold Controls recommends venting the air from the HVAC system to protect equipment from damage and limit noise.

· Converting 3 – Point Floating Actuators to On/Off Actuators

With more and more actuator manufacturers removing on/off control actuators from their product line, the Controls Contractor is forced to find ways to convert the standard three point floating actuators (also called tristate) to on/off actuators (also called two position).

· Fail-safe – Capacitor Return vs. Spring Return

A fail-safe actuator returns to a pre-set home position when power is removed from the actuator. In comparison a non fail-safe actuator stays in its last position when power is removed.

· Benefit of Using Flow Limiting Valves with Modulating Temperature Control Valves

Their function is to limit the flow to a pre-set value, and until the flow reaches that value the limiter is wide open and not concerned about the flow, similar to a current limiter or resistor in an electrical circuit.

· Using Automatic Valves to Determine System Pump Requirements

Griswold Controls automatic flow limiting valves make it a breeze to meet these demands. First, the system is automatically balanced. Second, if the pump is perfectly sized, when every branch in the system is flowing as designed

· Advantages of the Next Generation Stem

Griswold Controls’ evolutionary line of products featuring our patent pending field repairable stem design address these problems and reflect a response to changes taking place in processes within the HVAC industry that can impact product performance.

· Using the MVP® to Protect Your Chiller in a Variable Primary Flow System

The Griswold Controls’ MVP not only maintains a constant flow regardless pressure changes – but it also has a position display on the actuator. That means you can tell what position the actuator is in ant any time.

· 3-Way Control Valves or Pressure Independent Valves?

A 3-way control valve shuts off water flow in one pipe while opening water flow in another pipe. In a modulating or 3-point floating application the valve can also mix water from two different pipes into one pipe or divert water from one pipe into two different pipes.

· Converting Actuator Requiring 2-10vdc to Accept 4-20mA Signal

If your control systems sends a current signal these actuators can still be used by using a resistor to convert the current to voltage. This can easily be achieved by wiring a 500 ohm resistor between the common port on an actuator and the 2-10 vdc signal port.

· Side Stream Filters

Side stream filters are installed on almost every commercial hydronic system, diverting a small portion of the total flow from the discharge of a circulating pump through the filter, and back to the pump inlet

· Using Control Valves For Heat Pump Applications

Griswold Controls’ Balance Zone and Unimizer valves meet the requirements for  heat pump applications.

· Summary Sheet: California Prop 65 Guidelines AND Pressure Testing with Air vs Water

Other states however follow California’s Prop 65 guidelines that say brass is allowed for domestic water as long as the lead content is below 5%.
Pressure testing with either air or water to detect leakage is a common practice in our industry.