Pneumatic Testing - Safe Distances from Stored Energy Calculations
Pneumatic testing is often used to test piping systems when the presence of moisture is undesirable or removal of residual water cannot be conveniently achieved. Due to incompressibe nature of hydrotest fluid, the energy stored in a piping system under hydrostatic pressure is far less in comparison to a piping system which is subjected to pneumatic pressure.
- Piping Topic: Testing
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Introduction to Hot Taps - Guidelines for Design and Installation
Hot tap is a pressure installation technique that allows connections to be made on existing live (operating) piping or equipment without shutdown or interruption to critical plant operation. As per API Publication 2201, "Hot tapping is the technique of attaching connections to equipment in service by welding and drilling."
- Piping Topic: Hot Tapping
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Pipe Weight Calculator - Steel Pipes
Online calculator for pipe weight is a convenient tool for instantly calculating the weight of steel pipes and its contents including any insulation weight if applicable. Choose the pipe size and the applicable thickness to calculate the empty pipe unit weight.
- Piping Topic: Weight Calculations
- Hits: 15176
Allowable Stress for Piping Materials as per ASME B31.3
Section 302.3.2 (d) of ASME B31.3 provides the basis of design stress or allowable stress for piping materials. As per this section, the basic allowable stress values at temperature for materials other than bolting materials, cast iron, and malleable iron shall not exceed the lowest of the following for temperatures below the creep range:
- Piping Topic: Stress Theory
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Allowable Pipe Support Span Calculation
Selecting the correct pipe support span is an important aspect of piping design. The maximum pipe support spacing is dependent on the maximum allowable deflection or sag in the piping and the maximum permissible longitudinal stress on account of the span.
- Piping Topic: Support Span Calculations
- Hits: 27049
Pipe Wall Thickness Calculation for Straight Pipe under External Pressure
Calculation for a straight pipe under external pressure is referenced in section 304.1.3 of ASME B31.3. As per this section, to determine wall thickness and stiffening requirements for straight pipe under external pressure, the procedure outlined in the BPV Code, Section VIII, Division 1, UG-28 through UG-30 shall be followed, using as the design length L, the running centerline length between any two sections stiffened in accordance with UG-29.
- Piping Topic: Wall Thickness Calculations
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RTRP (GRE GRP GRV) Piping Specification & Performance Testing
The application of reinforced thermosetting resin pressure piping (RTRP) has grown considerably in chemical plants, oil and gas facilities, water and sewarage systems due its corrosion resistance, strength and durability. FRP, GRP, GRE and GRV are abbreviations for specific types of RTR pipes depending on the resin systems used in the manufacture of piping system.
- Piping Topic: FRP and GRP
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Piping Fabrication Tolerances - Metallic Piping
Piping prefabrication is an important step in the construction of piping systems. Whenever feasible, sections of piping systems or piping spools are prefabricated by the contractor in the workshop. After prefabricating the spools, they are transported to the field and assembled to complete the piping system.
- Piping Topic: Fabrication
- Hits: 30685
What is a Piping and Instrumentation Diagram (P&ID)
Piping and Instrumentation Diagram (P&ID) is a schematic representation of a process flow between all process units or equipment's in a plant. As the name suggests the graphical representation on a P&ID includes all piping connected between equipment's and the associated instrumentation necessary to design, construct and operate a plant facility.
- Piping Topic: Process Plant Layout
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Pipe Supports and Restraints - Types and Functions
In the design of piping systems, the piping engineer or designer is responsible for locating the pipe supports and restraints to take care of the loads and displacements imposed on the piping system for the various load cases. A piping system may have several types of supports and restraints to take care of the various loads imposed on it and to allow the piping system to function safely under operating, design and occassional load conditions.
- Piping Topic: Supports General
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Bitumen Pipeline Design Considerations
The installation of hot bitumen pipeline (on-lease) requires careful consideration with regards to design and construction methodology. The buried pipelines are routed through congested areas within lease boundary, hence various factors are taken into consideration including design constraints.
- Piping Topic: Pipeline Design
- Hits: 6391
Acoustic Induced Vibration - AIV in Piping Systems
Acoustic Induced Vibration (AIV) is a flow induced vibration phenomena that can result in fatigue failures in piping systems leading to major safety and economic consequences such as damage to assets, environmental impact and loss of life.
- Piping Topic: Stress Theory
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Pipeline Pigging - Purpose, Pig Types and Procedure
Pipeline pigging is the process of propelling a pig through a pipeline from a pig launcher and receiving the pig at the pig receiver end of the pipeline. Various types of pigs are propelled through the pipeline depending on the intended function which could be cleaning, dewatering, chemical batching, dimensioning or inspection.
- Piping Topic: Pipeline Design
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What is Piping Engineering and Design
Piping Engineering is a specialized discipline of Mechanical Engineering which covers the design of piping and layout of equipments and process units in chemical, petrochemical or hydrocarbon facilities. Piping Engineers are responsible for the layout of overall plant facilities, the location of equipments and process units in the plot and the design of the connected piping as per the applicable codes and standards to ensure safe operation of the facilities for the design life.
- Piping Topic: Process Plant Layout
- Hits: 38386

Hydrotest Procedure for Piping Systems
Testing requirements for piping systems are covered in para. 345 of ASME B31.3 code. As per ASME B31.3, prior to initial operation and after completion of applicable examinations as per para. 341, each piping system shall be tested to ensure tightness. The recommended test is a hydrostatic leak test.
- Piping Topic: Testing
- Hits: 30233
DBB or DIB pipeline ball valve for Scraper Trap isolation
Double Block and Bleed (DBB) trunnion-mounted ball valves have been traditionally used on pipelines for isolation of pig traps or scraper traps. DBB design ball valves have provision for venting of the body cavity to verify that both upstream and downstream seats provide effective sealing against the line pressure.
- Piping Topic: Ball Valve
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Spiral Wound Gasket Design, Materials and Application
A spiral wound gasket consists of spirally wound (usually V-section) metal strip with filler material and an outer metallic ring to hold the windings in place. Spiral wound gaskets are categorized as semi-metallic gaskets and their design is covered by ASME B16.20 - Metallic gaskets for pipe flanges. A spiral wound gasket is designed for one time use.
- Piping Topic: Gasket Design
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Calculation of Bolt Torque for Flanged Joint Assembly
Most failures of bolted joints are due to poor assembly and application of incorrect bolting torque. Hence it is important to ensure correct tightening of bolts to ensure leak free joints.
The torue applied to a bolt is used to overcome the following friction:
- Piping Topic: Bolt Design
- Hits: 39744
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Pipe Supports - Prevention of Crevice Corrosion
Uninsulated or bare piping resting directly on structural steel have resulted in repeated corrosion problems posing high risks for pipe leaks. The geometry of bare piping resting on structural steel provides a crevice that allows water to be trapped.
- Piping Topic: Supports General
- Hits: 8864
What is Hydrogen Induced Cracking
The presence of hydrogen at high temperature and pressure can cause embrittlement of carbon steel and alloy steels. Atomic hydrogen is able to permeate into steel and reacts with iron carbides to form methane. The methane accumulates at the grain boundaries and cannot diffuse through the metal resulting in high internal stresses that eventually lead to cracking of the metal at the grain boundary.
- Piping Topic: Materials Corrosion
- Hits: 5479
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