Welcome to Warm Floor Comfort!

Therm-X-Trol Expansion Tanks

The heating system, insulated from the atmosphere, has a certain capacity. Internal hydraulic pressure in a closed system filled with water at elevated temperatures and a desire to expand the water rises and can exceed the tensile strength of its individual components. Therefore, in hot water heating systems introduced damper - Therm-X-Trol expansion tank.

The main purpose of the expansion tank - welcome increase in the volume of water in the system, formed when it is heated to maintain a certain hydrostatic pressure. In addition, the Therm-X-Trol tank is designed to fill the loss of water in the system with negligible leakage and lowering its temperature. Through an open tank removed excess water in the gutter overflow system.

The second important purpose of the Therm-X-Trol expansion tank - a collection of air escaping from the water during its heating in the boiler. The air in the system gets to the tap water, which at room temperature, it dissolved about 40 mg / liter. When heated to maksimalnoraschetnoy the room temperature (+95 ° C) solubility of air decreases to about 3 mg / liter. Outputs of the air bubbles float in the water flow on the main standpipe in the expansion tank, from which are removed in the atmosphere.

Therm-X-Trol Expansion tanks like Amtrol ST-12 Therm-X-Trol Expansion Tank have a number of disadvantages: they are cumbersome, and therefore difficult to place them in the premises and increase the useless loss of heat through their walls with the location of tanks outside. In addition, the open (not sealed) tank water absorbs from the atmosphere, which increases the internal corrosion of pipes and appliances.

Open expansion tank placed above the uppermost point of the heating system, usually in attic of the building or on the staircase and covered with thermal insulation.

Therm-X-Trol Tanks are manufactured in standard sizes for standard drawings, cylindrical or rectangular, sheet steel top and supplying manhole for inspection and painting. In case the tank, there are several inlets:

• Pipe 1 is designed for connection of the expansion pipe which water enters the tank;
• Pipe 4 - (at the bottom) for circulation pipes through which water is allocated for the heating system;
• Pipe 3 - for the control (signaling) pipes;
• Nipple 2 - to connect the tank with the overflow pipe, communicating with the atmosphere.

The control pipe 3 of the conclusions to the sink and supply shut-off valve. Issue of water when you open the faucet should indicate the presence of water in the tank, and hence in the system (water level should not be lower than shown in Fig. 53 dash-dot line).

Net capacity Amtrol ST-5 Therm-X-Trol Expansion Tank, limited high hp (Fig. 53), should correspond to an increase in the volume of water filling the heating system when it is heated to an average calculated temperature.

Application of reduction, in principle, increase energy costs for operation of heating networks (as opposed to full bore ball valves, pressure drop which can be ignored). We can assume that the operating expenditure of energy proportional to the ratio of pressure drop in a separate ball valve (local pressure drop 5rm) to a linear pressure drop in a pipeline FP6:

Manufacturers of ball valves with reduced bore in their directories lead coefficient ?, obtained experimentally, for different pipe diameters. It is assumed that t, for a full bore ball valve is zero.

Fig. table presents data firm Ballomax (circles) for ball valves with an angle of 90 degrees increase in the range of conditional passes from 50 mm to 500 mm. Nominal bore of the pipeline corresponds to figure, a conditional pass for ball valves - one standard size smaller. This figure also shows the "average" data (solid line), with which it is convenient to compare the experimental values of t,, submitted by various firms. Homogenization was carried out by the method of least squares.

Fig. 2 shows the firm Klinger for ball valves with an angle of 16O expansion in the range of conditional passes from 250 mm to 800 mm. Straight lines 1 -4 correspond to the reduction of 1, 2, 3 and 4 sizes. This figure also represented by their corresponding experimental data. Averaging in Fig. 2 held in the same manner as in Fig. 1.

The average values of the coefficient of local resistance t, reduced ball valves according to figures 1 and 2 for port areas in the range from 100 mm to 800 mm and with a reduction from 1 to 4 sizes in the table.

In the second row of the table - the data in Figure 2 (reduction coefficient a - «Ballomax»), the third to sixth - the data in Figure 3 (reduction coefficient 1-4 - «Klinger»).

As outlined in the table data (1 and 2 rows and columns 6-10) we can conclude that the coefficients of ball valves in the range of conditional passes 250 mm - 500 mm and with a reduction of one standard size differ by no more than 20%, which appears to be within experimental error. Consequently, the ratio of ball valves in the specified range of conditioned aisles of the angle of expansion is almost independent.

In addition, according to table the coefficient of ball valves with the reduction decreases with increasing port area and the sharper, the greater the reduction coefficient.

Fig. 3 shows the coefficient a (the relative proportion of the loss), calculated by the formula (2), where values as a function of conditional pass D taken from Fig. 2. ke and l in the calculation were taken to be 0.0005 m and 1000 m respectively.

Thus, to estimate the magnitude of the pressure losses in heat networks in the application of reduced ball valves, you need to compare the pressure loss in them with corresponding loss of pressure in the line pipe per unit length. As an example, we estimate these losses for D = 500 mm. In this case, according to Figure 2, 0 (500) = 0.25 and 3 (500) = 3.7 (the reduction coefficient 1 and 4, respectively). Then the formula (2) the loss would amount to 1.3 Pa / m and 15 Pa / m for these coefficients reduction. We also note that the value 0 (500) is comparable with the value in smooth bends with R = 4D [2].

Findings

Consideration of the application of reduced cranes can draw the following conclusions. The fact that according to the formula (2), with branches of the arteries may have a more significant loss at the length of plots below 1000 m, is not significant in the overall pressure loss, as these values are not aggregated in determining the total losses on the highway.

Application of reduced ball valves in radiant heating systems is possible in the following cases:

• One standard size in relation to the diameter of the tube (without the technical and economic calculations);
• Two or more standard size - if there is excessive pressure on the branch to the head sections of heat networks;
• The main (longest line) is necessary techno-economic calculation (comparison of energy loss during throttled and save capital expenditure).

PEX Tubing, Radiant Heat Manifolds, Taco Circulator Pumps, Takagi Water Heaters