ASME B30.4-2015 pdf download
ASME B30.4-2015 pdf download.Portal and Pedestal Cranes.
(c) Displacement of a support during testing is reason to refrain from placing the crane in operation until an evaluation is made by a qualified person.
(d) Before placing a crane in service, all functional motions, locking devices, and brakes shall be checked for operation. Limiting devices shall be checked for proper setting and operation.
(e) Functional motion tests shall be performed first without load and then at rated load, or where appropriate, with the overload test load boomed-in to rated radius. The tests shall include
(1) load hoisting and lowering
(2) boom hoisting and lowering or traversing the trolley
(3) swing motion
(4) brakes and clutches
(5) limit, locking, and safety devices
‘f) The trip setting of hoist limit devices should be determined by tests, with an empty hook comprising a series of runs each at increasing hook speed up to the maximum speed. The actuating mechanism of the limit device shall be located so that it will trip the device, under all conditions, in sufficient time to prevent contact of the lower load block with the upper load block or boom point sheaves.
‘g) The order in which tests of a newly erected crane are to be performed is as follows:
(1) functional motion test without load
(2) functional motion tests at rated load
(3) overload tests of supports
SECTION 4-1.2: LOAD RATINGS AND STABILITY
:15) 4-1.2.1 Load Ratings Where Stability Governs Lifting Performance
(a) For each stipulated operating radius, the load rating is established by taking a percentage of the load that by calculation produces a condition of incipient tipping when the boom is in the least stable direction. Under static conditions, the load ratings shall not exceed 67% of the calculated tipping loads. When wind is considered, if applicable, the combined effects of static and wind loads shall not exceed 77% of the calculated tipping load.
(Ii) A nonsymmetrical mounting may require a considerably higher loading to produce a tipping condition in a direction other than the least stable direction for which basic load ratings have been established. Therefore, if the crane specification includes ratings for other than the least stable direction, such ratings shall not exceed the applicable tipping percentages.
(c) For a load at any operating radius, stability is affected by the length of boom, jib, or combination of boom and jib mounted, counterweight arrangement, and, when applicable, tower height. The manufacturer shall take these conditions into account when establishing load ratings. Each load rating shall therefore be determined for the least stable permitted configuration governed by the rating.
(d) Wind forces shall be determined using the maximum operating wind speed applied in the direction least favorable to stability.
(e) For cranes designed to travel with load, inertia forces and forces induced by the maximum allowable track variation from level, as specified by the manufacturer, shall be considered in establishing load ratings.
(‘ In addition to the above, the following stipulations shall apply to the establishment of load ratings:
(1) Incipient tipping exists when the algebraic sum of the overturning (tipping) moments equals the sum of the stabilizing moments.
(2) The crane is mounted level, except as in (e) above.
(3) Lifting attachments that are a permanent part of the crane in its working condition shall be considered part of the load for stability calculations whether or not such attachments are part of the published load ratings.
4-1.2.2 Load Ratings Where Factors Other Than Stability Govern Lifting Performance
(a) For each stipulated operating radius, the manufacturer shall ascertain that the crane is capable of supporting rated loads without stresses exceeding predetermined acceptable values. Dynamic effects associated with hoisting and slewing shall be considered, and wind, if applicable, shall be taken in the least favorable direction and at the maximum in-service velocity, as specified by the manufacturer.
(b) Under any condition of loading, stresses may be affected by boom or jib length, counterweight arrangement, tower height (when applicable), swing speed changes and other dynamic effects, hoist line reeving, and hoisting speed range. Therefore, the structural, mechanical, hydraulic, electrical, or pneumatic competence shall be evaluated for the least favorable con figuration and operating conditions covered by given load ratings.
(c) A nonsymmetrical mounting may require a considerably higher loading to produce a tipping condition in a direction other than the least stable direction for which basic load ratings have been established.
