Dielectric Unionfor electrical conduit

Install the copper solder adapter onto the copper pipe, then melt the copper solder adapter to the copper pipe with a propane flame. Try to keep the plastic insulator as far away from the torch as possible to prevent the melting the insulator.

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Calculate Reynolds number with this easy to use calculator. Determine if flow is laminar or turbulent. Applicable for liquids and gases.

This is the expression of law of head conservation to the flow of fluid in a conduit or streamline and is known as Bernoulli equation:

If the velocity of fluid inside the pipe is small, streamlines will be in straight parallel lines. As the velocity of fluid inside the pipe gradually increase, streamlines will continue to be straight and parallel with the pipe wall until velocity is reached when the streamlines will waver and suddenly break into diffused patterns. The velocity at which this occurs is called "critical velocity". At velocities higher than "critical", the streamlines are dispersed at random throughout the pipe.

where is: p - pressure; pt - total pressure; v - velocity; ρ - density;

where is: Z1,2 - elevation above reference level; p1,2 - absolute pressure; v1,2 - velocity; ρ1,2 - density; g - acceleration of gravity

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The Darcy equation can be used for both laminar and turbulent flow regime and for any liquid in a pipe. With some restrictions, Darcy equation can be used for gases and vapors. Darcy formula applies when pipe diameter and fluid density is constant and the pipe is relatively straight.

where is: D - internal pipe diameter; v - velocity; ρ - density; ν - kinematic viscosity; μ - dynamic viscosity;

A-Cover the threads of the steel pipe with many layers of pipe sealing tape. The steel pipe should be connected to the threaded end of the dielectric union body. A pipe wrench should be used to tighten the union as you turn it clockwise.

Virgin Engineers is a notable manufacturer, supplier ad stockist of Dielectric Unions in Mumbai, India. Dielectric Union are utilized in commercial and residential applications to prevent galvanic and stray currents from accelerating corrosion and degradation in the pipe system. It is inserted between two pipes composed of different metals. Dielectric unions are available in a variety of designs, sizes, and materials.

where is: f - friction factor; Re - Reynolds number; D - internal pipe diameter; kr - pipe roughness;

Most common equation used for friction coefficient calculation is Colebrook-White formula and it is used for the turbulent flow in the pressure drop calculator:

A-In an electrolytic reaction, water serves as the electrolyte and occurs when two dissimilar metals come into contact. Corrosion then starts to occur in the metals. Galvanic corrosion is what this is. The pipes made of various metals are joined together using dielectric unions to avoid this happening. When there is poor water quality and galvanized materials have a high probability of corroding, brass is frequently utilized for fittings for copper pipes. Brass is sensitive to acidic water despite being rust-resistant.

If the flow is laminar and Reynolds number is smaller than 2000, the friction factor may be determined from the equation:

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where is: δ - boundary layer thickness; D - internal pipe diameter; Re - Reynolds number;

If you need a quick calculation, but you are not still familiar how to use the calculator, you can order calculation service from the calculator developer.

As in real piping system, losses of energy are existing and energy is being added to or taken from the fluid (using pumps and turbines) these must be included in the Bernoulli equation.

Physical values in Darcy formula are very obvious and can be easily obtained when pipe properties are known like D - pipe internal diameter, L - pipe length and when flow rate is known, velocity can be easily calculated using continuity equation. The only value that needs to be determined experimentally is friction factor. For laminar flow regime Re < 2000, friction factor can be calculated, but for turbulent flow regime where is Re > 4000 experimentally obtained results are used. In the critical zone, where is Reynolds number between 2000 and 4000, both laminar and turbulent flow regime might occur, so friction factor is indeterminate and has lower limits for laminar flow, and upper limits based on turbulent flow conditions.

where is: Z1,2 - elevation above reference level; p1,2 - absolute pressure; v1,2 - velocity; ρ1,2 - density; hL - head loss due to friction in the pipe; Hp - pump head; HT - turbine head; g - acceleration of gravity;

Flow in pipe is always creating energy loss due to friction. Energy loss can be measured like static pressure drop in the direction of fluid flow with two gauges. General equation for pressure drop, known as Darcy's formula expressed in meters of fluid is:

where is: D - internal pipe diameter; q - volumetric flow rate; v - velocity; A - pipe cross section area.

Calculate pipe diameter for known flow rate and velocity. Calculate flow velocity for known pipe diameter and flow rate. Convert from volumetric to mass flow rate. Calculate volumetric flow rate of ideal gas at different conditions of pressure and temperature.

where is: Δ p - pressure drop due to friction in the pipe; ρ - density; f - friction coefficient; L - pipe length; v - velocity; D - internal pipe diameter; Q - volumetric flow rate;

A-To prevent galvanic corrosion, two-part fittings of different metals that are electrically insulated from one another are referred to as dielectric unions. The phrase is frequently used to refer to a group of plumbing pipe fittings. Two distinct metals exposed to an acidic solution can experience galvanic corrosion. A current of electricity flows between the two metals as a result of this mixture, which functions as a battery.

Flow in pipes is considered to be laminar if Reynolds number is less than 2320, and turbulent if the Reynolds number is greater than 4000. Between these two values is "critical" zone where the flow can be laminar or turbulent or in the process of change and is mainly unpredictable.

The pressure drop is the function of internal diameter with the fifth power. With time in service, the interior of the pipe becomes encrusted with dirt, scale and it is often prudent to make allowance for expected diameter changes. Also roughness may be expected to increase with use due to corrosion or incrustation at a rate determined by the pipe material and nature of the fluid.

Velocity of fluid in pipe is not uniform across section area. Therefore a mean velocity is used and it is calculated by the continuity equation for the steady flow as:

Static pressure is pressure of fluid in flow stream. Total pressure is pressure of fluid when it is brought to rest, i.e. velocity is reduced to 0.

When flow is turbulent and Reynolds number is higher than 4000, the friction factor depends on pipe relative roughness as well as on the Reynolds number. Relative pipe roughness is the roughness of the pipe wall compared to pipe diameter e/D. Since the internal pipe roughness is actually independent of pipe diameter, pipes with smaller pipe diameter will have higher relative roughness than pipes with bigger diameter and therefore pipes with smaller diameters will have higher friction factors than pipes with bigger diameters of the same material.

Most widely accepted and used data for friction factor in Darcy formula is the Moody diagram. On Moody diagram friction factor can be determined based on the value of Reynolds number and relative roughness.

where is: M - Mach number M=v/c - relation between local fluid and local sound velocity; γ - isentropic coefficient;

In the turbulent regime of flow, there is always a thin layer of fluid at pipe wall which is moving in laminar flow. That layer is known as the boundary layer or laminar sub-layer. To determine flow regime use Reynolds number calculator.

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If friction losses are neglected and no energy is added to, or taken from a piping system, the total head, H, which is the sum of the elevation head, the pressure head and the velocity head will be constant for any point of fluid streamline.

When the velocity is greater than "critical", the regime of flow is turbulent. In turbulent regime of flow there is irregular random motion of fluid particles in directions transverse to the direction on main flow. Velocity change in turbulent flow is more uniform than in laminar.

To express this equation like pressure drop in newtons per square meter (Pascals) substitution of proper units leads to:

where is: q - flow rate [m3/h]; ρ - density of fluid [kg/m3]; c - specific heat of fluid [kJ/kgK]; Δ T - temperature difference [K]; P - power [kW];

where is: hL - head loss due to friction in the pipe; f - friction coefficient; L - pipe length; v - velocity; D - internal pipe diameter; g - acceleration of gravity;

where is: p - pressure; pti - total pressure; v - velocity; M - Mach number; γ - isentropic coefficient;

The regime of flow when velocity is lower than "critical" is called laminar flow (or viscous or streamline flow). At laminar regime of flow the velocity is highest on the pipe axis, and on the wall the velocity is equal to zero.

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When calculating Reynolds number for non-circular cross section equivalent diameter (four time hydraulic radius d=4xRh) is used and hydraulic radius can be calculated as:

The nature of flow in pipe, by the work of Osborne Reynolds, is depending on the pipe diameter, the density and viscosity of the flowing fluid and the velocity of the flow. Dimensionless Reynolds number is used, and is combination of these four variables and may be considered to be ratio of dynamic forces of mass flow to the shear stress due to viscosity. Reynolds number is:

It applies to square, rectangular, oval or circular conduit when not flowing with full section. Because of great variety of fluids being handled in modern industrial processes, a single equation which can be used for the flow of any fluid in pipe offers big advantages. That equation is Darcy formula, but one factor - the friction factor has to be determined experimentally. This formula has a wide application in the field of fluid mechanics and is used extensively throughout on this web site.

Bernoulli equation equation is used in several calculators on this site like pressure drop and flow rate calculator, Venturi tube flow rate meter and Venturi effect calculator and orifice plate sizing and flow rate calculator.

Calculate heat energy and thermal power for known flow rate. Calculate flow rate for known heat energy or thermal power. Applicable for boilers, heat exchangers, radiators, chillers, air heaters.

where is: p - pressure; pt - total pressure; pd - dynamic pressure; v - velocity; ρ - density;

For compressible flow calculation gas state equation can be used. For ideal gases, velocity for Mach number M < 1 is calculated using following equation:

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When the thickness of laminar sub layer (laminar boundary layer δ) is bigger than the pipe roughness e the flow is called flow in hydraulically smooth pipe and Blasius equation can be used:

This relation can be used to calculate required flow rate of, for example, water heated in the boiler, if the power of boiler is known. In that case temperature difference in above equation is the change of temperature of fluid in front and after the boiler. It should be said that efficiency coefficient should be included in above equation, for precise calculation.

If dynamic pressure is measured using instruments like Prandtl probe or Pitot tube velocity can be calculated in one point of stream line as:

With the open threaded end facing out, slid the union nut over the end of the copper pipe. Additionally, the copper pipe must be covered by the orange plastic insulator as illustrated.

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Calculator based on Darcy equation. Calculate pressure drop for known flow rate or calculate flow rate for known pressure drop. Friction factor calculation included. Applicable for laminar and turbulent flow, circular or rectangular duct.

A dielectric union is a special adapter or fitting used in various metal pipe systems to isolate the connection of dissimilar metals. An elastomeric rubber gasket seals the connection, and a plastic composite material separates the copper tube connection from the dielectric union's hex nut. When different metals come into touch with each other, they begin to corrode. The little amount of acid in water initiates the electrolytic reaction between the two metals, causing electrons to flow from one metal to the other. This eventually leads to galvanic corrosion. To prevent this from happening, a dielectric union is employed to connect the two dissimilar metal pipes.

Total pressure can be calculated using Bernoulli theorem. Imagining that flow is in one point of stream line stopped without any energy loss Bernoulli theorem can be written as:

where is: p - pressure; pt - total pressure; pd - dynamic pressure; v - velocity; ρ - density;

Union nut and union body are put together by sliding the rubber gasket between them. You should clockwise-twist the union nut with a pipe wrench.