JB/T 7334-2016 English PDF (JBT7334-2016)

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JB/T 7334-2016: Hand chain blocks
JB/T 7334-2016
JB
MECHANICAL INDUSTRY STANDARD
OF THE PEOPLE’S REPUBLIC OF CHINA
ICS 53.020.99
J 80
Filing No.: 56466-2017
Replacing JB/T 7334-2007
Hand chain blocks
手拉葫芦
ISSUED ON: OCTOBER 22, 2016
IMPLEMENTED ON: APRIL 01, 2017
Issued by: Ministry of Industry and Information Technology of PRC
Table of Contents
Foreword ... 4 
1 Scope ... 6 
2 Normative references ... 6 
3 Basic parameters ... 7 
4 Technical requirements ... 8 
4.1 Temperature of operating environment ... 8 
4.2 Performance ... 9 
4.3 Main parts ... 11 
4.4 Appearance and painting ... 12 
4.5 Safety protection ... 12 
5 Test method ... 13 
5.1 Test load ... 13 
5.2 Visual inspection ... 13 
5.3 No-load performance test ... 13 
5.4 Light load performance test ... 13 
5.5 Dynamic load performance test ... 14 
5.6 Braking performance test ... 14 
5.7 Determination of hand pull ... 14 
5.8 Continuous action performance test ... 15 
5.9 Limit strength test of whole machine ... 15 
5.10 Strength test of whole machine ... 16 
5.11 Determination of the minimum distance between two hooks and the lifting
height ... 16 
5.12 Determination of paint film adhesion ... 16 
5.13 Determination of load limit ... 17 
6 Inspection rules ... 17 
6.1 Inspection classification ... 17 
6.2 Exit-factory inspection ... 17 
6.3 Type inspection ... 18 
7 Marking, packaging, transportation, storage ... 18 
7.1 Marking ... 18 
7.2 Packaging ... 19 
7.3 Transportation and storage ... 19 
Hand chain blocks
1 Scope
This standard specifies the basic parameters, technical requirements, test
methods, inspection rules, marking, packaging, transportation, storage of hand
chain blocks.
This standard applies to chain blocks, for general use, which are driven by
involute spur gears.
This standard does not apply to hand chain blocks, which are used in explosive
environments.
2 Normative references
The following documents are indispensable for the application of this document.
For dated reference documents, only the dated version applies to this document.
For undated reference documents, the latest version (including all amendments)
is applicable to this document.
GB/T 9286 Paints and varnishes - Cross cut test for films
GB/T 10051.1 Lifting hooks - Part 1: Mechanical properties, lifting capacities,
stresses and materials
GB/T 13306 Plates
GB/T 13384 General specifications for packing of mechanical and electrical
product
GB/T 20947 Short-link chain for lifting purposes - Grade T (types T DAT and
DT) fine-tolerance hoist chain
GB/T 30026 Short link chains for lifting purposes - Grade TH, fine tolerance
for manually operated chain blocks
GB/T 30027 Short link chains for lifting purposes - Grade VH, fine tolerance
for manually operated chain blocks
JB/T 4207.1 Hooks for manually operated lifting equipment
continuous lifting and lowering operations (one operation consists a cycle of
lifting, stop, lowering, stop). After the test of the hand chain block, each part
shall not have abnormal phenomena; meanwhile they shall meet the
requirements of 4.2.3 and 4.2.4.
4.2.7 Limit strength of whole machine
By releasing the brake, to make the tail ring limiting device work. The hand
chain block shall be able to reliably bear the static tensile load, which is 2.5
times the rated capacity; meanwhile there shall be no damage.
4.2.8 Strength of whole machine
The hand chain block shall be able to reliably support a static tensile load, which
is 4 times the rated capacity, for 10 minutes.
4.2.9 Lifting height
The lifting height of the hand chain block shall not be less than the specified
value. It should not be greater than 12 m.
4.3 Main parts
4.3.1 Hook
When the rated capacity is not more than 25 t, the hook shall meet the
requirements of JB/T 4207.1. When the rated capacity is more than 25 t, the
mechanical properties and materials of the hook shall meet the requirements of
GB/T 10051.1. The hook shall be able to rotate 360° on a horizontal surface.
The lower hook shall be equipped with a locking device.
4.3.2 Lifting chain
The lifting chain shall meet the requirements of GB/T 30026 or GB/T 30027,
OR meet the requirements of the T-type chain, which is specified in GB/T 20947.
4.3.3 Hand chain
The length of the hand chain should be equal to the lifting height of the hand
chain block; however, it is allowed to be less than 200 mm shorter than the
lifting height. The mechanical properties shall meet the requirements of Table
7. The connecting ring of the hand chain may be exempted from welding;
however, there shall be no deformation, that affects the use under the pulling
force of the ultimate working load.
value of the load limit protection device shall be in the range of 1.3 ~ 1.8 times
the rated capacity. At the same time, it shall ensure that the lowering load
function of the hand chain block is not affected.
4.5.2 The hand chain block shall be equipped with a tail ring limiting device. It
shall meet the requirements of 4.2.7.
5 Test method
5.1 Test load
The test load can adopt the direct loading method by heavy objects, OR
hydraulic pressure OR other loading methods that can generate test loads.
When using the heavy object method to load, the allowable deviation of the test
load is ±1%. When hydraulic pressure or other loading methods, that can
generate test loads, are used, the allowable deviation of the test load is 0 ~
10%. The heavy object loading method shall be adopted as the basis for
arbitration.
5.2 Visual inspection
The visual inspection shall include whether the specifications and/or status of
all important components meet the requirements, such as:
- Hand chain, chain guide, chain stop device, brake;
- All protective devices, including protective covers, tail ring restraints, etc.;
- Hook and its connecting parts;
- Lifting chains, lifting sprockets, loose pulley and their fasteners.
5.3 No-load performance test
Hang the hand chain block on the support. Pull the hand chain, by manual
method, under no-load condition. Raise and lower the lower hook once,
according to the test lifting height as specified in Table 4.
5.4 Light load performance test
Install the hand chain block on the test bench. According to the test load as
specified in 4.2.2 AND the test lifting height as specified in Table 4, operate the
measured. The turning angle of the lifting sprocket is converted by the number
of loops of the hand chains. Use the electrical measurement method as the
basis for arbitration.
5.7.3 Determination by heavy weight method
When using the heavy weight method to determine, first hang the load of the
rated capacity, on the hand chain block to be tested. Lift it according to the test
lifting height as specified in Table 4. Then adjust the position of the lifting
sprocket, so that it is at the position, where the maximum torque is applied from
the lifting chain. Use hands to tighten the hand chain on the descending side.
Hang the test weight and additional weight, on the hand chain, at the lifting side.
The additional weight is 50% of the test weight. The test weight is hanging near
the hand chain wheel. The additional weight is hanging at a position 200 mm
from the stroke limit surface. Then let go instantly. The two weights will drop at
the same time. When the additional weight is in place and stop, the test weight