An Introduction to Pipe Hanger Types , Application , And Design

An Introduction to Pipe Hanger Types , Application , And Design


Introduction
The pipe support is an assembly of components, including a device or method used as a direct attachment to the structure, a means of securing the pipe, and a connecting member extending from the structure attachment to the device used to secure the pipe. Other devices include pipe restraints or anchors and pipe guides.

Types Of Hangers And Supports
Attachment to Structure Various methods and devices are used to attach the support to the structure. Typical attachments include:
1. An insert is installed at the time the slab is poured. An anchor or expansion bolt is installed after the slab is poured.

FIG 1

2. A beam clamp  provides attachment to exposed structural members. Beam clamps can also be welded to the beam.

FIG 2

3. Brackets  attach to walls.

FIG 3

The manufacturer of each type of attachment will have specifications for the maximum loading permitted for each type of attachment

A hanger is the device used to secure the pipe to the hanger rod. It must not distort, cut, or abrade any pipe while allowing free movement. There is a wide variety to choose from, including:
1. Pipe clamps  support pipes passing through openings in floors.

FIG 4

2. Saddles  support pipe from floors.

FIG 5

3. Trapeze hangers support multiple pipes.

FIG 6

4. A clevis hanger  is an adjustable hanger for a single pipe.

FIG 7

A variety of pipe support materials and devices are available. Specialized supports or pipe hangers are made for almost every possible situation you will encounter during your duties (figure 8 .9.10)

FIG 8

.

Type 1 Adjustable steel clevis hanger (figure 9)
A pipe attachment for suspension of horizontal stationary lines and providing a means for vertical adjustment.
Type 2 Yoke-type pipe clamp
A pipe attachment for suspension of horizontal stationary insulated lines. This type of clamp is also made to accommodate pipe of nonstandard size when designed with a filler plate.
Type 3 Carbon- or alloy-steel three-bolt pipe clamp
A pipe attachment for suspension of horizontal stationary lines.
Type 4 Steel pipe clamp
A pipe attachment for suspension of horizontal stationary insulated lines.
Type 5 Pipe hanger
A pipe attachment for suspension of horizontal stationary lines either using a hanger rod or bolting to wall from the T slot provided in the side of the strap.
Type 6 Adjustable swivel pipe, split ring type or solid ring type
A pipe attachment for suspension of horizontal stationary lines.
Type 7 Adjustable steel band hanger
A pipe attachment for suspension of horizontal stationary lines and providing a means for vertical adjustment.
Type 8 Extension pipe or riser clamp
A pipe attachment for suspension of vertcal stationary lines without the use of hanger rods. The transfer of piping load is accomplished by resting the ears of the clamp on a bearing surface.
Type 9 Adjustable band hanger
A pipe attachment for suspension of horizontal stationary lines.
Type 10 Adjustable swivel ring, band type
A pipe attachment for suspension of horizontal stationary lines and providing a means for vertical adjustment.
Type 11 Split pipe ring with or without turnbuckle adjustment
A pipe attachment for suspension of horizontal stationary lines permitting installation before or after pipe is in place.
Type 12 Extension split pipe clamp, hinged or two-bolt
A pipe attachment for suspension of horizontal stationary lines used in conjunction with a pipe nipple.
Type 13 Steel turnbuckle
A device with one left-hand internal threaded end and one right-hand internal threaded end, used to join two threaded rods and providing for vertical adjustment.
Type 14 Steel clevis
A device which provides for the attachment of a threaded rod to a bolted or pinned connection.
Type 15 Swivel turnbuckle
A device which provides flexibility at the pipe connection and a means of vertical adjustment.
Type 16 Malleable iron socket
A device for attaching threaded rods to various types of building attachments.
Type 17 Steel weldless eye nut
A forged-steel device which provides for the attachment of a threaded rod to a bolt or pin connection.
Type 18 Steel or malleable concrete insert
A cast-in-place device which provides for a rod attachment capable of nominal lateral adjustment.
Type 19 Top beam C-clamp
A device requiring no welding which attaches to the top flange of a structural shape where the vertical rod is required to be offset from the edge of the flange.
Type 20 Side beam or channel clamp
A device requiring no welding which attaches to the bottom flange of a structural shape where the vertical rod is required to be at the edge of the flange.
Type 21 Center beam
A device requiring no welding which attaches to the bottom flange of a structural shape where the vertical rod is required to be centered on the structural shape.
Type 22 Welded beam attachment (as shown or inverted less bolt)
A structural attachment welded to the bottom of steel beams and used as a means for connecting hanger rods to the beams.
Type 23 C-clamp
A device requiring no welding which attaches to a flange of a structural shape and provides for attaching a threaded rod.
Type 24 U-bolt
A U-shaped rod with threaded ends used as a support or guide.
Type 25 Top beam clamp
A device requiring no welding which attaches to the top flange of a structural shape where the vertical rod is required to be at the edge of the flange.
Type 26 Pipe clip
A pipe attachment for suspension of horizontal stationary lines by bolting the clip directly to a structure. Also referred to as a pipe strap or strap.
Type 27 Side beam clamp
A device requiring no welding which attaches to the bottom flange of a structural shape where the vertical rod is required to be offset from the center of the shape.
Type 28 Steel beam clamp with eye nut
A device requiring no welding which attaches to the bottom flange of a structural shape where the vertical rod is required to be centered on the structural shape.
Type 29 Linked steel clamp with eye nut
A device requiring no welding which attaches to the bottom flange of a structural shape where the vertical rod is required to be centered on the structural shape.
Type 30 Malleable beam clamp with extension piece
A device requiring no welding which attaches to the bottom flange of a structural shape where the vertical rod is required to be centered on the structural shape.
Type 31 Light welded steel bracket
A braced cantilever device intended for supporting a gravity load from rod-type hangers. This device is typically bolted to a wall and may be installed with the brace either above or below the horizontal member.
Type 32 Medium welded steel bracket
A braced cantilever device intended for supporting maximum gravity loads and/or horizontal loads up to 1500 lb (6670 newton, N). Loads may be applied anywhere along the main member. This device is typically bolted to a wall and may be installed with the brace above, below, or on either side of the main member.
Type 33 Heavy welded steel bracket
A braced cantilever device intended for supporting maximum gravity loads and/or horizontal loads up to 3000 lb (13,340 newton, N). Loads may be applied anywhere along the main member. This device is typically bolted to a wall and may be installed with the brace above, below, or on either side of the main member.
Type 34 Side beam bracket
A device requiring no welding which attaches to the sides of steel or wooden members and provides a means for vertical adjustment.
Type 35 Pipe slide and slide plate
A device for supporting piping having horizontal movements and where a low coefficient of friction is necessary.
Type 36 Pipe saddle support
A device having a curved base for cradling horizontal pipe and which slips into a nominal diameter pipe stanchion.
Type 37 Pipe stanchion saddle
A device having a curved base for cradling horizontal pipe and which slips into a nominal diameter pipe stanchion. The U-bolt yoke provides stability.

FIG 9

Type 38 Adjustable pipe saddle support
A device having a curved base for cradling horizontal pipe and which threads into a nominal diameter pipe stanchion. This device provides vertical adjustment.
Type 39 Steel pipe-covering protection saddle
A device used on insulated piping which is designed to minimize heat losses and prevent damage to insulation.
Type 40 Protection saddle
A metal device intended to prevent crushing of insulation and/or breaching of the vapor barrier. It is typically used at support points.
Type 41 Single pipe roll
A device used for supporting horizontal piping from two rods, allowing for vertical adjustment and consisting of a roller that allows for axial movement with virtually no frictional resistance.
Type 42 Carbon- or alloy-steel riser clamp
A pipe attachment for supporting vertical piping through the use of shear lugs welded to the pipe. Load bolts are provided to transfer the pipe load to the rod hanger assembly.
Type 43 Adjustable roller hanger with or without swivel
A device used for supporting horizontal piping from a single rod, allowing for vertical adjustment and consisting of a roller that allows for axial movement with virtually no frictional resistance.
Type 44 Pipe roll complete
A device used for supporting horizontal piping where vertical adjustment is unnecessary and consisting of a roller that allows for axial movement with virtually no frictional resistance.
Type 45 Pipe roll and plate
A device used to support horizontal piping, having minimal axial movement, from beneath and where no vertical adjustment is necessary.
Type 46 Adjustable pipe roll and base
A device used to support horizontal piping, having axial movement, from beneath and where vertical adjustment is necessary.
Type 47 Restraint control device
A rigid, mechanical, spring, or hydraulic device used for absorbing shock loading and/or controlling sway in piping systems.
Type 48 Spring cushion
A noncalibrated, rod-type, single-coil spring support used where a cushioning effect is desired.
Type 49 Spring cushion roll
A non-calibrated, rod-type, double-coil rod spring support used where a cushioning effect is desired along with a pipe roll.
Type 50 Spring sway brace
A spring device used for absorbing shock loading and/or controlling sway in piping systems.
Type 51 Variable spring hanger
A device having a single-spring coil which supports the gravity loads of piping systems that are subjected to vertical thermal movements. This device produces a varying load when the piping moves from the cold position to the hot position. This type of spring hanger supports the pipe from above.
Type 52 Variable spring base support
A device having a single-spring coil which supports the gravity loads of piping systems that are subjected to vertical thermal movements. This device produces a varying load when the piping moves from the cold to the hot position. This type of spring hanger supports the pipe from below.
Type 53 Variable spring trapeze hanger
A device having double-spring coils which support the gravity loads of piping systems that are subjected to vertical thermal movements. This device produces a varying load when the piping moves from the cold position to its hot position. This type of spring hanger supports the pipe from above with two rods.
Type 54 Constant support hanger, horizontal type
A device having a single-spring coil working in conjunction with counter balancing mechanisms to support the gravity loads of piping systems that are subjected to vertical thermal movements. This device produces a constant load when the piping moves from the cold position to the hot position. This type of constant hanger has the spring coil in the horizontal position and supports the pipe from above.
Type 55 Constant support hanger, vertical type
A device having a single-spring coil working in conjunction with counter balancing mechanisms to support the gravity loads of piping systems that are subjected to vertical thermal movements. This device produces a constant load when the piping moves from the cold position to the hot position. This type of constant hanger has the spring coil in the vertical position and supports the pipe from above.
Type 56 Constant support hanger, trapeze type
A device having double-spring coils working in conjunction with counter balancing mechanisms to support the gravity loads of piping systems that are subjected to vertical thermal movements. This device produces a constant load when the piping moves from the cold position to the hot position. This type of constant hanger has the spring coil in the vertical position and supports the pipe from below with two rods.
Type 57 Plate lug
A structural attachment which provides a means of connecting rod type hangers to structural steel members via a pin or bolt through the hole of the lug.
Type 58 Horizontal traveler
A device which permits the structural attachment end of rod-type hangers to accommodate horizontal piping movements in conditions where offsetting of conventional structural attachments is not practical due to limited space.

FIG 10

Classification of Pipe Supports Based on Details, Constructions and Functions
Classification of Pipe Supports Broadly the pipe supports are classified in three groups as per following details / functions:
– General details
– Construction details
– Functions ie. Purpose

1. Pipe Supports Classification as per General Details:
A pipe line needs to be supported from a foundation or a structure. The piping loads will be acting on these foundations / structures. Since these foundations / structures are built on ground, they will exert an equal and opposite reaction, while supporting the pipe.
In a pipe support, there will be some parts of support arrangement which is directly attached to the pipeline and there will be some other parts which shall be directly attached to the foundation / structure supporting the pipe.
As per this general detail the support is classified as:
1.1 Primary Supports:
It is the parts of support assembly which is directly connected to the pipe.
1.2 Secondary Supports:
It is the parts of support assembly which is directly connected to the foundation / structure and is supporting the primary support attached to the pipe line.

2. Pipe Supports Classification as per Construction:
Based on construction details, pipe supports are broadly classified in three types, as
– RIGID SUPPORTS
– ELASTIC SUPPORTS
– ADJUSTABLE SUPPORTS

These are described below in brief.

2.1 Rigid Supports:
This type of support arrangement is generally very simple and has maximum use in piping. It does not have adjustability to the erection tolerances. It will directly rest on foundation or structure which is supporting the pipe. Common type of RIGID SUPPORTS are shoe type (welded), shoe type (with clamp) Trunnion type, valve holder type, support brackets (Secondary Support). These are described under the topic ‘Supports Generally used’.

FIG 11

2.2 Elastic Supports:
This type of support is commonly used for supporting hot piping. It shall be able to support pipes even when the pipe is moving up or down at support point.
Common types of elastic supports are variable type spring supports, constant type spring supports. These are described under the topic ‘Supports generally used ‘.

FIG 12

2.3 Adjustable Supports:
This type of support is Rigid type in construction but is has few nuts and bolts arrangements for adjusting the supports with respect to the actual erected condition of pipe. The support can be adjusted for the erection tolerances in the piping. These are required for a better supporting need at critical locations of pipe supports.

FIG 13

Mostly all type of rigid supports can be modified by using certain type of nuts and bolts arrangement, to make it as an Adjustable support.
Only a typical type of adjustable support is described under the topic ‘Supports Generally used.’

3. Pipe Supports Classification as per Function (i.e. Purpose)

FIG 14

Pipe supports classified as per functions are summarized in the Table at FIG.14. These are shown along with its basic construction, the symbols generally used and type of restraints it offers to the piping system.

The supports classified as per function are further described as follows:

3.1 Loose Support:
This is most commonly used support meant for supporting only the pipe weight vertically. It allows pipe to move in axial as well as transverse direction but restricts only the vertical downward movement.

3.2 Longitudinal Guide:
This type of support is used to restrict the movement of pipe in transverse direction i.e. perpendicular to length of pipe but allow movement in longitudinal direction. This is also a commonly used type of support. Generally it is used along with Loose support.

3.3 Transverse Guide:
This type of support is used to restrict the movement of pipe in longitudinal (axial) direction but allows the pipe to move in transverse direction. This is also referred as ‘AXIAL STOP’. This type is less used as compared to above two types. Generally it is used along with Loose support.

3.4 Fixed point/Anchor:
FIX POINT type of support is used to restrict movements in all three directions. ANCHOR type of support is used to restrict movement in all three directions and rotation also in these three directions.

Non-Welded Type (Fix Point):
This can be considered as a combination of longitudinal and transverse guide. This type resists only the linear movements in all directions but not the rotational movements. This avoids heavy loading of support as well as pipe. Therefore this type of support is preferred over welded type.

Welded Type (Anchor)
This type of support prevents total movements i.e. linear as well as rotational. This type of support is used when it is absolutely essential to prevent any moment/force being transferred further. It causes heavy loading on support as well as pipe.

3.5 Limit Stop:
As name itself indicates it allows pipe movement freely upto a certain limit and restricts any further movement. This is useful when total stops causes excessive loading on piping and support or nozzle.
This type of support should be used selectively, because of stringent and complicated requirements of design, erection and operation.

3.6 Special Supports:
When we need a pipe support whose construction or functional details are different from the available details, then a special support detail sketch is prepared. The functions of this support can be any combination of above functions.
Materials

Pipe supports are fabricated from a variety of materials including structural steel, carbon steel, stainless steel, galvanized steel, aluminum, ductile iron and FRP composites. Most pipe supports are coated to protect against moisture and corrosion. Some methods for corrosion protection include: painting, zinc coatings, hot dip galvanizing or a combination of these. In the case of FRP composite pipe supports, the elements required to form a corrosion cell aren't present, so no additional coatings or protections are necessary

PIPE HANGER SIZING

Considerations for Designs the pipe supports  with a minimum of effort :
- Operating Load or Installed Load
- Pipe Displacement at the Pipe Support
- Installed Height (Support) or Length (Hanger)
- Pipe Diameter
- Temperature of the Pipe
- Pipe Support Assembly or Sequence of Components Desired

the hanger assembly shall be selected to support the total weight of the piping. The procedure used to

calculate the total weight is as follows:

FIG 15

the weight of the pipe using the following formula:

W = F × 10.68 × T × (O.D. − T)

where :

 W = weight of pipe, lb/ft

F = relative weight factor, see Table 1

T = wall thickness of pipe

O.D. = outside diameter of pipe, in

TABLE 1

the weight of insulation on the pipe. For standard insulation and thickness, use the following formula:

W = F × D

where 
W = weight of insulation, lb/ft³

F = relative weight factor for insulation, see Table 2

D = density of insulation, lb/ft³

TABLE 2

Basis of the Pipe Deflection

FIG 16

Up to 650°F,  

Above 650°F,

  

Where : 

E = 30 x 10⁶ (psi)

A = Deflection (in )

L = Pipe length (ft )

O.D. = Outside diameter of pipe (in )

S A = Stress (kips/sq in)

kip = kilo-pounds (1000 lb )

Hanger Rods

The hanger rod is usually threaded and connects the attachment to the hanger that is threaded to receive the rod. The diameter of the rod is selected by the amount of weight it will support, which is determined by the area of the rod at the root of the thread. The safe weight capable of being supported by different rod diameters is shown in Table 3 ,4

TABLE 3

TABLE 4

Expansion Loops

To calculate the length required to absorb movement without damage, the following formula is used:

where 

L = pipe leg length, ft

D = nominal outside diameter of pipe, in

ΔC = change of dimension of pipe run, in

.

hanger spacing

Hangers for straight runs For straight runs, you can use both flexible and rigid couplings. When rigid couplings are used, the same hanger spacing as other piping methods can be applied. You can refer to the hanger spacing standards of ANSI B31.1 Power Piping Code, B31.9 Building Services Piping Code, NFPA 13 Sprinkler Systems, or Mechanical Equipment Construction Guide (Japan). See the table below.

TABLE 5

1) ANSI B31.1 Power Piping Code
2) ANSI B31.9 Building Services Piping Code
3) NFPA 13 Sprinkler systems
4) Ministry of Land & Transportation of Japan: Mechanical Equipment Construction Guide