Pipe Supports:

1. General:

  Type and location of pipe supports including shoes, anchors, spring hangers, and guides shall be indicated on isometrics and/or orthographic piping drawing for 2 inch lines or larger. Support locations for 1.5 inch and smaller lines shall be shown when such lines are critical.


2. Pipe Support Shoes:

  Hot-insulated lines 2 inch and larger, and all steam-traced lines, shall be provided with support shoes at all support locations.

  Shoes supporting stress-relieved lines shall be clamp-on type. Standard lengths of support shoes:

    12 inch for up to 3 inch thermal movement in each direction.
    18 inch for up to 6 inch thermal movement in each direction.
    24 inch for 6 in. to 9 inch thermal movement in each direction.
    36 inch for 9 inch to 15 inch thermal movement in each direction.

  Cold-insulated lines shall have support shoes strapped to the outside of the insulation at the support points.

  Guides and anchors designed for small to medium forces may be used with shoes strapped on to the outside of the cold-insulation of piping.


3. Lines from Vertical Vessels:

  Support brackets for 6 inch and smaller lines will be designed as single-bracket.
  For lines 8 inch and larger, double-bracket type as required.

4. Lines over Exchangers:

  Supports shall be attached to the exchanger saddle, shell flange or its foundation.


5. Lines from Horizontal Drums:

  Lines from nozzles on top of vessels to grade may be supported from grade guided near the center of the vessel.


6. Piping at Pumps and Turbines:

  Piping 3 inch and larger shall be supported by adjustable base supports to the structural members or by non-adjustable types supported to grouted-in base plate.

  If possible pavement frost heave or settlements, base supports shall rest on the pump foundation or a structural member attached to its foundation.


7. Relief Valves:

  Piping connected to relief valves shall be supported.


8. Mechanical Support Devices:

  Variable spring supports shall be used for supporting lines and equipment with a vertical thermal movement up to 3 inch.

  Constant supports shall be used for supporting lines and equipment with a vertical thermal movement more than 3 inch.


9. Tank field Piping:

  Lines connected to tanks subject to settlement shall have the first support located at sufficient distances from the tank to avoid excessive stress.
For large settlement, the lines shall be supported from the tank or by adjustable or spring supports from grade.


Pipe Rack Design:


1. Basic Design:

  Braced bay should be located away from bays where pumps or similar equipment are to be located in the vicinity of column line.
  To provide flexibility for future expansion, no piping should run on the center line of columns except flare line.
  Pipe rack bents are spaced 20 feet on centers, the others carrying small tubing or electrical conduit may be 10 feet.


2. Transverse Beams:

  Unbraced length of the compression flange should be between points of inflection.
  Effects of torsion should be considered for anchor forces.


3. Longitudinal Beams:

  Beam struts should be designed for 50% of gravity loading on the most heavily loaded transverse pipe support beam.
  The above load should not be added to the design load for column or footing.


4. Vertical Bracing:

  The maximum spacing of braced bay should be 200 feet, normally 120 feet.


5. Column for Weak Axis:

  The unbraced length is from the base to the first longitudinal beam.
  Effective length factor k =1.0 for pinned base, k=0.7 for fixed base.


6. Column for Strong Axis (Sway Frames):

  The unbraced length is from the base to the first transverse beam.
  Rigid frame with pinned base, for effective length factor (k=2.5), GL=10.
  Rigid frame with fixed base, for effective length factor (k=1.5), GL =1.
  Knee frame with pinned base, for effective length factor (k=3.0), GU =10 and GL =10, but KL does not need to exceed the KL if the frame was designed as a moment connected rigid frame.
  Knee frame with fixed base, for effective length factor (k=1.9), GU =10 and GL =1, but KL does not need to exceed the KL if the frame was designed as a moment connected rigid frame.


7. Structure Sway:

  a). Pipe rack frames:

    For 30 years wind, Height / 150.
    For 10 years wind, Height / 180.
    1.2 inch for support 18 feet above grade.
    2.0 inch for support 30 feet above grade.

  b). Equipment Support Structures:

    For 30 years wind, Height / 200.
    For 10 years wind, Height / 240.
    2.3 inch at the equipment floor 46 feet above grade.
    3.0 inch at the equipment floor 60 feet above grade.

  c). Industrial Building Frames:

    For 30 years wind, Height / 170.
    For 10 years wind, Height / 200.
    2.4 inch at the top of a 40 feet tall building frame.
    2.0 inch for support 30 feet above grade.

  d). Vertical deflection of platform:

    Vertical deflection of platform framing beams = span / 300.
    Vertical deflection of equipment support points due to the 50% live load and the operating liquid weight = 3/8 inch.


8. Deflection Limits:

  a). Cable tray and pipe supports:

    Horizontal, Height / 200.
    Vertical, Height / 180.

  b). Platform and walkways: Length / 180.


Foundation and Grout:

1. Foundation:

  a). Foundations shall be placed a minimum of 10 feet below grade or shall be insulated to reduce the frost penetration to less than the depth of the underside of the foundation.

  b). The supports for all tanks, vessels and pipes shall be designed for hydrotest.

  c). Foundations supporting rotating equipment not as a heavy one shall be:

    The ratio of weight of concrete to weight of equipment shall not be less than 3 to 1 for rotary, 5 to 1 for reciprocating one.
    Min. 2 rows of ties provided around anchor bolts in the top of pedestals, A horizontal layer of temperature steel provided in the top of pedestals.

  d). All graded-supported concrete paving slab shall be isolated from columns and foundations by expansion joints.

  e). Top of concrete piers for structures or equipment shall be = 8 inch above HPFS (high point of finished surface).

  f). Foundation or pedestal inside buildings shall be = 6 inch above HPFS.

  g). Anchor bolt sleeves be provided at foundations for Spheres, Coker, Vertical Vessels, Pumps, Compressors, Heaters, and Boilers, free standing stacks, etc.

  h). Two nuts be provided at crane columns and at base of structures having vibrating and reversal loads.

  i). Frost adhesion for the foundation surfaces: Concrete 65 kPa, Steel 100 kPa.


2. Grout:

  a). Non-shrink cementitious grout, Compressive strength 30 MPa to 55 MPa :

    Centrifugal equipment less than 100 HP (except use in hydrocarbon).
    Constant wet environment will not exist.
    Wet-dry cycling associated with exterior use will not occur.

  b). Non-shrink epoxy grout, Compressive strength 55 MPa to 80 MPa :

    Reciprocating or centrifugal equipment greater than 100 HP.
    Constant wet environment will exist.
    Wet-dry cycling associated with exterior use will occur.

  c). Non-shrink high-temperature grout, Compressive strength 35 MPa: High-temperature up to 500 degree.

  d). Grout holes for placement of the grout should be located so that grout does not travel more than about 48 in. (1.2m).

    Holes for pumping grout are typically 3/4 to 2 in. (19 to 50 mm) in diameter.

  Grout holes for free-pouring grout are typically 3 to 6 in. (75 to 150 mm) in diameter.

    e). If anchor bolt sleeves are to be grouted, anchor bolt sleeves and holes should be grouted before pouring grout under the plate.

    For post-tensioned anchor bolts with sleeves, sleeves shall be not grouted, a greese or mastic type filler should be filled inside the sleeves

  f). For hydraulic cement grouts, the concrete surface should be continuously saturated with water for at least 24 hours just prior to grouting

    For epoxy grout, the surface should be dry unless otherwise specified by the manufacturer.

Design Loads:

1. Loads for Pipeway:

  a). Load for piping and cable tray shall be dead load.

  b). The actual vertical load from pipes be used but shall be = 2.0 kPa on each level, the effects of large pipes and snow load shall also be considered.

  c). For miscellaneous pipe supports, minimum load = 1.2 kPa.

  d). Thermal expansion forces shall be:

    10% of total operating weight of all pipes.
    30% of the operating weight of the largest pipe.
    On supports having three lines or less, 20% of the total pipe weight.
  e). Anchor loads 9kN shall be considered to act at 1/4 points of the beam.

  f). For electrical loads, a minimum weight of 1.0 kPa shall be used for single tray, 2.0 kPa shall be used for double tray.


2. Thermal Forces:

  a). Friction coefficients:

    Steel to steel = 0.3
    Steel to concrete = 0.5
    Teflon to Teflon = 0.1
    Teflon to steel = 0.1
    Graphite to graphite = 0.15
    Lubrite plate on steel (temperature >= 250) = 0.2
    Lubrite plate on steel (temperature < 250) = 0.15
    Lubrite plate on steel (bearing stress < 3.5 MPa) = 0.18

  b). Teflon shall not be used if temperature exceeds 260 degree, stainless steel or lubrite shall be provided. Lubrite shall only be used if bearing and/or temperature ratings are exceeded on Teflon.


3. Maintenance Load (live load):

  a). Tube bundle removal horizontal force for exchanger equal to the empty bundle weight or 8.9 kN whichever is greater.

  b). The force is applied at the centroid of the tube bundle.



4. Impact Loads (increased percentage):

  a). Hand operated cranes and monorail:

    Vertical = 10%.
    Lateral = 20%
    Longitudinal = 10%

  b). Electrically operated cranes and monorail:

    Vertical = 25%
    Lateral = 20%
    Longitudinal = 10%

  c). Davits, lifting Eyes and Supporting Structures:

    Vertical = 50%
    Lateral = 20%
    Longitudinal = 10%

  d). Vibrating Equipment:

    Elevator supports or Light machinery = 20%
    Heavy and reciprocating machinery = 50%
    Motor turbine driven equipment supports = 200%


5. Module Lifting and Transportation Load:

  a). The impact force due to lifting shall be 30% of weight of the module, therefore, the load combination 1.25(1.3V).

  b). The horizontal forces during transportation shall be:

  i) Off-Site:

    Longitudinal impact factor is 0.3g
    Transverse impact factor is 0.2g
    Vertical impact factor is 0.2g.
    Thus: load combinations: 1.25 (1.2V + 0.3L) and 1.25 (1.2V + 0.2T)

  ii) On-Site:

    Longitudinal impact factor is 0.1g
    Transverse impact factor is 0.05g
    Vertical impact factor is 0.
    Thus: load combinations: 1.25 (1.0V + 0.1L) and 1.25 (1.0 V +0.05 T)

  c). For lifting lug design, the applied loads including impact shall be multiplied by a factor 3 as a minimum (ASD).


6. Load Combination:

  Friction and wind or seismic loads are not combined,friction loads relieve themselves during wind and earthquake. Anchor load is different from friction loads, it should be combined with wind or seismic load

  Wind and earthquake loads are not considered to act simultaneously.

  Test load + live load + wind load shall be considered.