Installation Guidance of Boilers and Auxiliary Equipment

Boiler body installation

Before the boiler is in place, first check the equipment size according to the basic size, and the check size error should be within the requirements of the "General Specifications for the Construction and Acceptance of Mechanical Equipment Installation Engineering" (GB50231-98).

Inspection and installation of electric boiler

Before installation, you should be familiar with the drawings of boilers and ancillary equipment and the design drawings of boiler rooms, and check the approval of technical documents;

Check whether the equipment foundation has reached the installation strength, and the appearance of the foundation is not allowed to have honeycombs, pockmarks, cracks, holes, etc.;

For the foundation line, the foundation size and position should meet the following requirements:

After the boiler is in place, use the horn to level and align, the allowable deviation between the boiler and the foundation is ±2mm in the lateral direction, and the allowable deviation in the longitudinal direction is ±10mm.

Pump installation

Before installing the pump, the following inspections should be carried out on the pump:

Check according to the nameplate of the pump to determine whether the model of the pump is consistent with the model of the motor;

Check the equipment surface for damage and rust.

The installation of the pump body should meet the following requirements:

While checking, draw the center point of the four sides of the pump base (if there is no base, according to the relevant atlas on site) and the vertical and horizontal lines of the pump installation on the foundation;

Hoisting in place: when hoisting, the rope is tied to the lifting rings of the pump and motor, and the position of the base is adjusted so that the center point on the base coincides with the center line on the foundation;

Level adjustment: place the level ruler on the processing surface of the pump base to adjust the level of the pump, and the level should not exceed 0.1mm/m.

One pump with three valves: that is, the inlet of the pump should be equipped with a check valve and a butterfly valve, and the outlet should be equipped with a butterfly valve.

        The inlet and outlet pipes of the water pump are mostly flexible connections, and soft joints are installed at the inlet and outlet.

        The inlet and outlet of the water pump are 1 size smaller than the pipeline, and the inlet and outlet should be equipped with variable diameter short-circuits.

The horizontal suction pipe section connected to the pump should have a slope of 0.01-0.02, and the pump body should be at the highest part of the suction pipe.

Pipe installing

Before installing the pipe, the material of the pipe should be checked. All kinds of pipes should be laid along the wall to ensure installation and operation space and convenient maintenance.

Water supply pipeline installation

It should start from the nozzle end of the equipment, extend outwards based on the pipe interface on the equipment, and pay attention to the installation under the heating pipe.

Hot water pipe installation

When installing, it should have a certain slope, and the direction is the same as that of the hot water. The highest point is equipped with a steam exhaust valve, and the drainage pipe is connected to the ground drainage ditch. A trap is set at the lowest point to ensure easy operation.

Sewage pipe installation

Sewage pipes and equipment and valves are connected by flanges, and they are all welded. Elbows should be used as little as possible on pipes.

Valve installation

General requirements for valve installation

        The valve is installed in a location that is convenient for operation and maintenance while being aesthetically pleasing.

        When installed horizontally, the valve stem should be upward, not downward; the valve on the high-altitude pipeline can be installed horizontally.

        In the same room, the valves on the same equipment should be arranged symmetrically and neatly, and the appropriate height of the valves on the riser is 0-1.2 meters.

        Valves on side-by-side risers should preferably have the same center elevation.

        Valve brackets should be provided when installing heavier valves.

        Installation should pay attention to the valve arrow pointing in the same direction as the pipeline.

        When installing flanged valves, ensure that the end faces of the two flanges are parallel and concentric with each other. Double gaskets are not allowed.

        When installing a threaded valve, in order to facilitate disassembly, a threaded valve should be equipped with a joint (the installation of the joint is considered to facilitate maintenance, and usually the water flows through the valve first and then the joint).

        When installing flanged valves, be sure to tighten the bolts diagonally, and apply even force to prevent the asbestos pads from deviating or causing the valve body to deform.

        When the valve is connected to the pipe flange, the valve should be tightly closed; when the valve is welded, the valve should be slightly opened.

Installation of special valves

        A filter must be installed before the water inlet of the three-way valve and the solenoid valve.

        Installation of pressure reducing valve: stop valves and high and low pressure form gauges should be installed on both sides of the pressure reducing valve. The diameter of the pipe before decompression is 2-3# smaller than that after decompression, and the diameter of the pipe is 1-2# smaller than that of the pressure reducing valve when a bypass is installed; when it is used for steam pressure reduction, a drain pipe should be set.

        Trap installation: There must be stop valves before and after the trap, and a filter must be installed in front of the trap; the location of the trap should be as close to the drainage point as possible.

        Safety valve installation: The safety valve should be installed vertically; no valve can be set before and after the safety valve; the discharge pipe of the safety valve should be larger than the inlet of the safety valve, and the discharge pipe should be connected to a safe place.

        Installation of blowdown valve: gate valve should be installed before blowdown valve of hot water boiler; double blowdown valve should be installed for steam boiler.

Instrument installation

Pressure gauge installation

        Before installation, check whether the pressure gauge has a lead seal, and those without lead seal cannot be installed;

        The installation location is convenient for observation, cleaning and maintenance;

        It should be installed vertically on the straight pipe section, and should not be installed near the tee, elbow and reducer;

        The pressure gauge must have a trap and a three-way stopcock.

        Pressure gauges should be installed at the water inlet and outlet of each boiler and water pump.

Thermometer Installation

        The thermometer shall be installed in a position where maintenance and observation are convenient and free from mechanical damage; a thermometer shall be installed at the water inlet and outlet of each boiler.

        Install the bulb end as far as possible to the center of the tube.

Installation of other devices

        Plate heat exchanger installation: pay attention to distinguish the primary and secondary sides, and do not confuse them; the four ports of the plate heat exchanger must be equipped with thermometers and pressure gauges.

        Installation of gas collection tank: A gas collection tank is installed at the highest point of the water outlet of each pressure boiler; the exhaust pipes of the gas collection tanks are all welded, and the valves are flanged stop valves; the exhaust pipes are generally DN15-25.

       The decontamination device is installed on the main heating and return water main (the suction port of the circulating water pump), and is equipped with a bypass pipe; the location of the decontamination device is required to facilitate maintenance and sewage discharge.