7/12/2013

An Introduction to Pipe Supports

7/12/2013

Contents

Introduction Why Pipe Supports are Necessary? Codes and Standards of Pipe Supports Design and Selection of Pipe Supports Layout Considerations for Supporting General Support Terminology and basic function Types of Supports Typical Support Span for Rack Piping A brief about Spring Hanger Supports Pipe Support Manufacturers

7/12/2013

Introduction :-

Piping systems -Major Part of any hydrocarbon industry.

Pipes as irregular space frames –usually not self supporting.

Proper pipe support knowledge during layout stage is advantageous.

Loads to be transmitted from pipe to supporting structures with the help of pipe supports.

7/12/2013

Why Pipe supports are necessary ?

To prevent…..

Pipe stresses in excess to allowable.

Leakages in joints.

Line Vibrations.

Failure against Seismic and Wind loading.

Unintentional disengagement of piping from it’s supports.

7/12/2013

Why Pipe supports are necessary (Cont..) ?

To prevent…

• Excessive pipe sag.

• Exposure of elements to temp extremes, outside their design limit.

• Undesirable line movements to protect sensitive equipment against overloading.

7/12/2013

Codes and Standards on pipe supports.

MSS-SP-58- Establishes the material, design, and inspection criteria to be used in the manufacturing of standard pipe supports. (USA)

MSS-SP-69- Provides recommendations for the selection and application of pipe supports. (USA)

MSS-SP-89- Provides recommendations for the fabrication and installation of pipe supports. (USA)

BS-3974- Specification of pipe supports 1, 2, 3. (UK)

7/12/2013

VGB-R-510 L- Standard supports guidelines. (Germany)

RCC-M- Specifications for pipe supports. (France)

MITI 501- Technical regulations (Japan)

Various Pipe Support Manufacturers Catalogue (PTP/C&P /Lisega/ PSIL/ Sarathi etc)

Codes and Standards on pipe supports (Cont..)

7/12/2013

Design and selection of pipe supports

The complex requirement of today’s support elements:

Reliable functioning

Maintenance free operation

Economic and easy installations

Quick delivery of components and low unit prices

7/12/2013

Design and selection of pipe supports (Cont..)

Major Criteria governing support hardware :

• Support function,

• Magnitude of expected load,

• Space limitations,

• Design temp of piping system,

7/12/2013

Major Criteria governing support hardware (Cont..) :

• Expansion effects of piping systems.

• Piping attachment and supporting structure material compatibility.

• Piping insulation.

• Suitability to environment.

• Ease of operation, inspection and installation

Design and selection of pipe supports (Cont..)

7/12/2013

Layout considerations for Supporting.

Group pipe lines to minimize the number of structures needed . Route lines close to the possible point of supports ( i.e. grade or

structure which is provided for other purposes.) Supports or braces to be located at or near neutral pts. (thermal

null pts) Supports to be located as near as possible to concentrated loads

such as valves, flanges, heavy actuators etc. Piping susceptible to vibration such as compressor connected

lines to be supported independently. The use of hold down or similar supports offering resistance to motion and providing some damping capacity to be used rather than hanging type supports.

7/12/2013

Layout considerations…..

Piping connected to top of vessel to be advantageously supportedfrom the vessel to minimize relative movement between supports and piping.

Always maintain the distance between supports as per project specification recommended support span table. ( it is applicable to straight run pipe length only.) When change of direction in a horizontal plane occur, it is suggested that the spacing be limited to ¾ times the standard pipe span.

Sufficient space to be provided to facilitate support assembly installation, inspection and maintenance.

7/12/2013

General support terminology and basic function.

Restraint- Any device that prevents, resists, or limits the free thermal movement of piping.

Brace- A device primarily intended to resist displacement of piping due to forces other than thermal expansion and gravity.

Anchor- A rigid restraint providing substantially full fixation. Stop- A device which permits rotation but prevents translatory

movements of piping. Guide- A device which prevents the rotation about one or more

axis due to bending moment or torsion. Hanger- A support by which piping is suspended from a structure

which functions by carrying piping load in tension/Compression.

7/12/2013

General supports……

Resilient support- A support which includes one or more largely elastic members to carry pipe sustain + thermal loads at the same time allowing pipe thermal movement in the desired direction.

Sliding support- A device which is provided below piping to take gravity loads, offering no resistance other than frictional to horizontal motion.

Rigid support- A support providing stiffness in at least one direction, comparable to that of the pipe.

Damping element- A device which increases damping of a system offering high resistance against rapid displacement, caused by dynamic loading while permitting essentially free movement.

7/12/2013

Types of Supports

Hanger Supports – 1) Variable Hanger 2) Constant Hanger 3) Rigid Hanger.

Dynamically Loaded Supports – 1) Struts 2) Snubbers 3) Sway Brace 4) Energy absorbers 5) Pipe Clamps 6) Pipe whip / Hold down restraints.

Pipe Bearing Components – 1) Pipe Saddle 2) Pipe Shoe (welded/ clamped) 3) Pipe Trunnion 4) Wear Pad.

Threaded Members – 1) welding nut 2) welded beam attachment 3) Clevis 4) Turn buckle 5) Tie rod 6) Stud bolt, nut, locknut, spring washers etc.

Slide Bearing Plates – Teflon, Stainless steel, graphite. Pipe Supports for Cold Service.

7/12/2013

Typical Support Span for Rack Piping

Span table informs maximum support span for rest type supports when running in a Pipe rack.

The Span mainly depends on Material, Material Thickness, Commodity, Insulation thickness, layout, allowable deflection etc.

All span dimensions on the table are in “meter” length.

7/12/2013

Brief About Spring Hangers

Variable Spring HangerConstant Spring HangerBoth the above can be either hanging from top or Mounted from bottom.Main important terms related to Spring Hangers are:Cold Load, Hot Load, Spring Rate, Vertical Travel or Displacement, %Variability, Axial and Lateral Travel, Presetting, Bottoming Out, Elevation Difference etc.

7/12/2013

Pipe Support Manufacturers

Piping Technology and Products Ltd (PTP). Carpenter and Paterson Ltd (C&P). Lisega ltd. Binder Group Ltd. Pipe Support India Ltd (PSIL). Sarathi Engg Ent Pvt Ltd.

Friday, July 12, 201318 REAL, Jamnagar

7/12/2013

Questionnaire

Why pipe supports are required? What is the basic aim of supporting?

List three layout considerations for supporting?

List common types of supports in a piping system?

What do you mean by trunnion support?

As per analysis the nozzle loads on the pump are high due to friction. What is the type of support recommended near the equipment ?

7/12/2013

For a 10” NB line carrying liquid, Sch std what is the support span if the line is through a rack and having 50mm insulation?

What is the friction co-efficient value between PTFE and polished SS?

What do you mean by hot load and cold load of a Spring Hanger?

Write the equation for Variability? For a variable Spring hanger what is the maximum allowable value of variability as per C&P Catalogue?

Questionnaire (Cont..)

7/12/2013

Which type of support has restraints in all directions and degrees?

A rigid hanger is fixed on a horizontal pipe having 100 mm of travel, the hanger length is 700 mm . Is the design acceptable ?

Spring hangers are basically intended to carry a) Self weight or b) Thermal load?

The heater outlet line is having vibrations. In order to arrest the vibrations which type of restraints are to be used a) Sway Braceb ) Snubbers ?

Questionnaire (Cont..)

7/12/2013

Thank You