Ducts and pipes

Feeder belt feeder from the bottom of a hopper Belt feeder initially starts but suddenly stops with motor overload gap between the belt and hopper interface edge is too small/belt sags between pulleys/large FDI and small % difference between FDI and BDI. 

Pressure drops see Gas, Section 2.1 liquid Section 2.3. For control valves on the lines where flow is because of Ap between an upstream and downstream vessel, allow a Ap across the valve of 10% of the pressure of the lower terminal vessel or 50 % of the dynamic loss, whichever is greater. 

Velocities, see Gas, Section 2.1 and liquid. Section 2.3. Keep the velocity of compressible gases 0.6 sonic velocity. 

Sewer pipes have maximum flowrate when liquid level is 93 % of the diameter flowrate when full = flowrate when liquid level is 80% of the diameter. 

Schedule 40 = usual specification schedule 80 is heavy duty. 

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Usual Allowable Velocities for Duct and Piping Systems ... 

The fields of application are wide involving computational fluid dynamics (CFD), flow in ducts and pipes, pumps, fans, collection devices, pollution dispersal, and many other applications. 

Electrostatic precipitators have been used in various gas-cleaning applications almost for a century. During the past decades, a large number of modifi cations to electrostatic precipitators have been developed, the nn.ist common being duct and pipe types. The utilization of electrostatic precipitation extends from small household air cleaners up to huge industrial gas-cleaning systems. 

As closure progresses and dismantling of the facility advances, the workforce will be required to handle increasingly heavy materials and equipment. This equipment will include all possibly agent-contaminated machinery, metal ducts, and piping, as well as bulk materials such as concrete. Consequently, some risks to workers may be encountered more frequently during the dismantling and demolition associated with facility closure ... 

Through-the-roof ducts and pipes must have space between duct or pipe and curb adequately sealed. 

Custom Contact Molded Reinforced Polyester Chemical Resistant Process Equipment (PS15-69), a Department of Commerce Standard 15 years old, but still containing much useful information on materials and the manufacture of tanks, ducts and pipes. 

The electric current is induced into the ground by means of alternating anodes and cathodes. Anodes as well as cathodes are integrated into separate closed-loop pump systems, wherein electrolytes are circulated. Via these electrolytes, pH is controlled at a predetermined level, and the pollutants, transported by the groundwater, are captured by the electrodes under the influence of the applied potential (Fig. 17.1). Conditioning of the electrolytes as well as periodical removal of the contaminants from the electrolytes is effectuated in a special containerized installation. If necessary, electricity cables and extraction ducts and pipes can be installed underground. 

The electrolyte management and purification systems are housed in containers, together with the electrical power supply. If necessary, electricity cables and circulation ducts and pipes can be installed underground. 

FRICTION - Friction is the resistance found at the duct and piping waiis. Resistance creates a static pressure loss in systems. The primary purpose of a fan or pump is to produce a design volume of fluid at a pressure equal to the frictional resistance of the system and the other dynamic pressure losses of the components. 

Warning In all heat recovery schemes, it is very important to minimize transport losses keep ducts and pipes (for hot flue gas, hot air, and steam) short and very well insulated. Similarly, when preheating loads, if they must be transported hot, keep the distances short and cover them with insulation while being transported. 

These are followed by balance jobs such as fabricating/fixing prefabricated supports for ducts and pipelines, fabricating and then connecting ducts and piping to process vessels, installation of instrumentation probes and connecting cables, thermal insulation of process vessels and ducts/pipes. 

This is one of the very important prerequisites for the HAZOP studies for the plant. The technical teams shall specifically study all details of the P and ID made for the gas and liquid ducts and piping in the plant ... 

This is useful for detecting the heat losses from hot surfaces. The images shown by the camera indicate the presence of hot spots on surfaces of ducts and pipes (indicating inadequate or damaged insulation), furnaces, and process units (indicating inadequate or damaged internal refractory layers). The observations can be... 

Criterion 42 - Inspection of containment atmosphere cleanup systems. The containment atmosphere cleanup systems shall be designed to permit appropriate periodic inspection of important components, such as filter frames, ducts, and piping to assure the integrity and capability of the systems. 

Grounding, (i) All metal parts of spray booths, exhaust ducts, and piping systems conveying flammable or combustible liquids or aerated solids shall be properly electrically grounded in an effective and permanent manner. 

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