Primary/Secondary Boiler Piping

Installation and Service Manual

Example: The boiler inlet temperature is 160°F (71°C) and the boiler outlet temperature is 180°F (82°C), this means that there is a 20°F (11°C) temperature rise across the boiler.

Heat Exchanger Pressure Drop Chart

FIG. 34 Pressure Drop Chart 399,999 - 750,000

Pressure Drop Chart

990,000 - 2,070,000 Btu/hr Models

PRESSURE DROP IN FEET HEAD

FLOW IN GALLONS PER MINUTE

FIG. 35 Pressure Drop Chart 990,000 - 2,070,000

Circulator Pump Specifications

1.Maximum operating pressure for pump must exceed system operating pressure.

2.Maximum water temperature should not exceed nameplate rating.

3.Cast iron circulators may be used for closed loop systems.

4.A properly sized expansion tank must be installed near the boiler and on the suction side of the pump.

Circulator Pump Operation

(Heating Boilers Only)

The boiler pump should run continuously unless the boiler is provided with the pump delay control system. External wire leads are furnished with this option to allow the power supply for the pump to be switched across the normally open contacts of the relay, allowing the control relay to cycle the pump on each call for heat. The field installed boiler pump using the

factory supplied pump control system must not exceed 10 AMPS at 120VAC. As shipped from the factory, the control system is set to cycle the boiler pump on at each call for heat before the burners fire and run the pump for a 30 second period after the thermostat is satisfied. This will remove any residual heat from the combustion chamber before turning the pump off. See Wiring Diagram, page 64.

Pump Installation and Maintenance

For installation and maintenance information on the circulator pump, refer to pump manufacturers instructions included in the instruction package.

Boiler installations with a primary/secondary piping system as shown in FIG. 36 are recommended. This type of system uses a dedicated pump to supply flow to the boiler only. This secondary pump is sized based on desired boiler flow rate, boiler head loss and head loss in the secondary system piping only. A properly-sized primary (system) pump provides adequate flow to carry the heated boiler water to radiation, air over coils, etc. The points of connection to the primary (system) loop should be a maximum of 12" (or 4 pipe diameters) apart to ensure connection at a point of zero pressure drop in the primary system. Multiple boilers may also be installed with a primary/secondary manifold system as shown in FIG. 37. The multiple boilers are connected to the manifold in reverse return to assist in balancing flow to multiple boilers.

CAUTION: DO NOT allow the flow in the primary (system) loop to drop lower than the flow in the secondary loop at any time during boiler operation. Improper operation of the boiler(s) and possible tripping of the high limits and relief valves may occur.

The installer must ensure that the boiler has adequate flow without excessive temperature rise. Low system flow can result in overheating of the boiler water which can cause short burner on cycles, system noise and in extreme cases, a knocking flash to steam. These conditions indicate the need to increase boiler flow by installation of a larger circulator pump or the installation of a system bypass. System noise may also indicate an oversized boiler.

CAUTION: At no time should the system

pressure be less than 12 PSIG.

399, CF-CH(E)-i&s-08, 999 - 750 specifications

Lochinvar 999 - 750, CF-CH(E)-i&s-08,399 is a cutting-edge boiler designed for commercial heating applications. With its robust construction and high efficiency, this model stands out in the crowded market of heating solutions.

One of the main features of the Lochinvar 999 - 750 is its exceptional thermal efficiency rating. The unit incorporates advanced condensing technology that allows it to recover heat from flue gases, which helps in achieving efficiency levels of up to 99%. This efficiency not only reduces energy consumption but also lowers operational costs, making it an excellent investment for businesses looking to minimize their carbon footprint.

The boiler is designed to provide a powerful output of 750 kW, ensuring it meets the heating demands of larger buildings or commercial spaces. Its capacity makes it suitable for a range of applications including schools, hospitals, and industrial facilities. Moreover, the unit features a built-in cascading system that enables multiple boilers to be connected, enhancing system reliability and flexibility.

In terms of technology, the Lochinvar 999 - 750 is equipped with a user-friendly touchscreen interface. This innovative control system allows operators to monitor and adjust settings with ease, providing real-time performance data and alerts for maintenance needs. The intelligent controls optimize operation to match the heating load, further enhancing energy efficiency.

Safety is a top priority with this model. It is built with multiple safety features such as automatic shut-off valves, pressure relief valves, and flame monitoring systems, ensuring safe operation under various conditions. The unit also adheres to stringent industry standards and regulations, making it a reliable choice for commercial applications.

Furthermore, the Lochinvar 999 - 750 is designed with serviceability in mind. Its compact footprint and accessible components simplify maintenance, reducing downtime and associated costs. The unit also supports a variety of fuel sources, including natural gas, propane, and biodiesel, providing flexibility to meet different facility requirements.

In summary, the Lochinvar 999 - 750, CF-CH(E)-i&s-08,399 represents a blend of efficiency, reliability, and safety in commercial heating. Its advanced technologies and thoughtful design make it a powerful solution for various heating needs, making it an ideal choice for businesses aiming for excellence in energy management and operational efficiency.

Lochinvar 399, 999 - 750 Primary/Secondary Boiler Piping, Heat Exchanger Pressure Drop Chart

Models: 399 CF-CH(E)-i&s-08 999 - 750