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IS 13591 : 1992
CRITERIA FOR
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lndian Standard
c DESIGN OF LIFTING BEAMS
LJDC 626~422.24
@ BIS 1992
BUREAU OF INDIAN STANDARDS MANAK BHAVAN, 9 BAHADUR SHAH ZAFAR MARG
NEW DELHI 110002
November 1992 P&e Group 3
Hydraulic Gates and Valves Sectional Committee, RVD 12
FOREWORD
This Indian Standard was adopted by the Bureau of Indian Standards, after the draft finalized by the Hydraulic Gates and Valves Sectional Committee had been approved by the River Valley Division Council.
Lifting beams or lifting frames are used for handling gates stop logs and trash racks. The lifting beams/frames make it possible to engage and disengage the curves/hoist from the gate or trash-rack under water.
The limit of application ( depth of water ) of lifting beams frame will be set by the depth to which it is possible for a driver to work if it is required in case of failure of the beam. The lifting beam is operated under balanced condition and with clean grooves. For dirty grooves specially during construction the use ramming of lifting beams is not recommended because of frequent ramming.
For the purpose of deciding whether a particular requirement of this standard is complied with, the final value, observed or calculated, expressing the result of a test or analysis, shall be rounded off in accordance with IS 2 : 1960 ‘Rules for rounding off numerical values ( revised )‘. The number of significant places retained in the rounded off value should be the same as that of the specified value in this standard.
‘i
IS 13591 : 1992
Indian Standard
CRITERIA FOR DESIGN OF LIFTING BEAMS
1 SCOPE
1.1 This standard deals with criteria for design of three types of engaging and disengaging lifting beams.
2 GENERAL REQrJIREMENTS
2.1 The design of lifting bea.ms/frames should meet the following general requirements:
a)
b)
Cl
d)
4
A design with connection of lifting beam to the gate at one point of suspension can be used for small spans due to rise of gate when held at one single point.
The spacing between the guides of the lifting beam/frame should not be less than l/lOth of the span or 500 mm whichever is more.
If a lifting frame is used, the height of the frame should not be less than l/12 of span or 1 m whichever is more.
To provide greater stability the lifting beams should be equipped with two hoisting ropes or a suitable sling.
Spears or pilot rods should be provided on the gate to guide the book into proper position for grappling and to prevent rotation of the gate when raised above the guides.
For storing the lifting beam on the ground, suitable device should be provided so that the hooks are not touching the ground.
3 TYPE OF ENGAGING AND DISENGAGING LIFTING BEAMS
3.1 Depending upon the mode of engagement the lifting beams are classified as follows:
aj Manually operated lifting beams.
b) Automatic lifting beams.
c) Lifting beams with electro-hydraulic drive.
4 MANUALLY OPERATED LIFTlNG BEAMS
4.1 The lifting beam hooks and lifting lugs should be located symetrically about the central axis and should be in the line of C.G of the gate equipment to be lifted when the
1
lifting beam guide rollers are engaged in the guides. The lifting beam should be counter veighted as required to keep vertically when it s suspended ( see Fig. 1 ).
5 AUTOMATIC LIFTING BEAMS
5.1 Several type of engaging devices are used For such lifting beams. One of the arrange- ments which are recommended for use are given in 5.2.
5.2 Pipe and Socket Arrangement
The general arrangement of this type of lifting beams is shown in Fig. 2. The engage- ment and disengagement of both are performed after preliminary loading by hand of the grab device which operates under the action of falling load after receiving a mechanical impluse from a movable stop in the gate/trash rack. For reliable operation the following conditions should be fulfilled while designing the lifting beams:
a>
b)
cl
e)
The socket ( pipe ) in the gate should be made in such a manner that the pipe ( socket ) in the beam matches freely with it, taking into account the gaps in the grooves, the displacement of the engaging elements in the gate, and the possible wrapping of the beam.
To prevent the possibility of disengaging the beam from the gate, the beam should be made with a stop device controlled from a movable stop in the gate, which is brought into the operating position only when the gate is placed on the slit or the lower section.
To eliminate the possibility of free swinging of the gate with respect to the lifting beam when it is outside the groove the beam cantilivers should have lateral pipe which should enter freely into holes in the gate.
The block stem should descend freely by its own weight into the guides within the limits of preset travel.
The counterweight of the lever should have sufficient weight to produce the required torque to overcome the frictional forces in the hinges and
b
---
FIG. 1 TYPICAL DETAILS OF MANUALLY OPERATED LIFTING BEAM
IS 13591 : 1992
TYPICAL DETAILS OF AUTOMATIC LIFTING BEAM WITH PIPE AND SOCKET ARRANGEMENT
unforseen resistance in the coupling. which should be filled with working liquid
f) The axiai bearings, the shifts, and the and separated from the external medium
bushings should be made from anti- by a rubber diaphragm.
corrosive steel. 7 DOUBLE HOOK ARRANGEMENT
6 LIFTING BEAMS WITH ELECTRO- HYDRAULIC DRIVES
In this arrangement the pair of lifting hooks on the liftina beam is actuated bv a counter-
General arrangement of this type of lifting weight on aTever which is the preset in engag-
beams is shown in Fig. 3. The following ing or disengaging position. The movements
important points should be kept in view in of the hooks should be actuated by a single
designing this type of lifting beams: counter weights connected suitably to ensure synchronised operation. Four types with typical
a)
b)
Cl
d)
e)
f)
The hydraulic drive is provided by means arrangements are given in Pig.4, 5, 6 and~7.
of the servomotor. The servomotor 8 DESIGN should have sufficient capacity. After rotation of the grab by 90”, the oil should be pumped for some time through
8.1 Lifting beams should be designed for the
a safety valve and then a time relay capacity of the beam/the gantry crane which- ever is higher with impact factor of 1.1. The
should disconnect the electric motor. The disconnection may also be performed
permissible stresses should be limited to the values given below:
by an operator from the crane based on readings from grab position gauge. A induction type gauge should be kine- matically connected to the rotary stem. Two aditional induction gauges should be located at the ends of beam steel structure to signal the position of beam with respect to the gate. The cable leadouts should be heremitical
- a) Structural Steel
1)
2)
3)
4) sealed. To prevent possible infiltration of water into the frame in the drive end, a com- pensation chamber should be provided
Direct compression and compression in bending
Direct tension and tension in bending Shear stress
Combined stress
Bearing stress 5) b) Bronze or brass
1) Direct bearing stress
0.55 YP
0.55 YP
0.40 YP
0.75 YP 0.40 UTS
0.40 UTS
3
SlEEL BEAM
FIG. 3 TWICAL DETAILS OF LIFTING BEAM ELECTROHYDRAULIC DRIVE
8.2 Pinsconnecting the Lifting Beam, Lifting Hook, Side Guide, Etc
The pins should be of rolled/forged steel, be used for lifting beam with a factor of safety of 5. Deflection of frame or the structure as a whole ( without considering impact factor ) should be limited to span/SOO.
8.3 Design of Hook
The hooks are made out of plate steel and should be designed as curved beam.
The stress will be limited to that in lifting frame. At the engaging point the profile is to be hard faced to a maximum of 10 mm depth machined smoothly for uniform bearing of pin. In case the thickness of the hooks required more than the plate thickness the plates may be joined with rivet and welded.
8.4 Guide Rollers
The guide rollers/shoes should be provided on the sides of lifting beam to suit the gate groove
to limit lateral movement of gate to not more than 6 mm in either direction. The roller should be adjustable and travel on the guide tracks. Care should be taken that c.g. of the lifting hook should coincide with c.g. of gate, so that no lateral twist is permitted while lifting the gates.
8.5 Counter Weight
Suitable counter weight in the formation of dead weight should be added for lifting beam for self balance. The balance of lifting beam should be checked on the shop floor before using the lifting beam for operation in the vents.
8.6 Equipment Required for Handling Lifting Beams
The hoisting equipment used for lifting beams such as gantry crane, underslung hoist, etc. should be designed with fully balanced bottom blocks suitable for connecting the lifting beams. No lateral twist should be permitted while engaging the hooks. Before connecting the gate balancing of lifting beams should be tested preferably in dry condition.
4
FIG. 5 TYPICAL DETAILS OF LIFTING BEAM ARRANGEMENT WITH Two INTERLINKING AUTOMATIC ENGAGING AND DISENGAGING HOOKS - SECOND METHOD
CONNECT TO GANTRY CRANE FOLLOWER BEAM
OF FOLLOWER
FIG. 6 TYPICAL’ARRANGIZMENT OF LIFTING BEAM OPERATED FROM GANTRY CRANE WITH DOUBLE HOOK ARRANGEMENT
CONNECTIONS EROM
ul CO UNfER WE IGHT
PIG. 7 TYPICAL LIFTING BEAM WITH Two POINT SUSPENSION WITH DOUBLE HOOK ARRANGEMENT
6
.
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Dot : No.’ RVDtl2 ( 4692 1
Amendments lssued Since Publication
Amend No. Date of Issue Text Affected
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