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BSP/IS
TAPER THREAD SERIES
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| APPLICATION |
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Used
for fastening of pipe threads where pressure tight joints
are required on threads.
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| GENERAL |
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As
per specification the Internal threading is always Parallel
while External threading is, Hence following types of gauges
are used for checking the components. The Ring gauges are
used for checking external threading are always taper. While
the parallel internal threading can be checked either with
the help of Taper Plug gauge or with Parallel Plug gauge,
the choice depends on the customer and he has to clarify this
while placing order for gauges.
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| SPECIFICATION |
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Basic
Dimensions : IS 554 – 1985
ISO 7/1 - 1982
Gauging Practice : IS 8999/ 1979
BS 21/1985
ISO 7/2 – 1982
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| DIAMETER
- TPI COMBINATION. |
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NOM.DIA
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TPI
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1/16"
& 1/8"
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28
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¼"
& 3/8"
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19
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½"
& ¾"
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14
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1"
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11
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1.1/4"
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11
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1.1/2"
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11
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2"
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11
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2.1/2"
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11
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3"
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11
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4"
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11
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5"
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11
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6"
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11
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| CLASS
OF FIT |
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There
are Two classes. System 'A' and System 'B'
System 'A' Gauges do not have step and end face
corresponds to basic limit. External equipments are
requred to determine whether the component lies between
maximum and minimum limit.
System 'B' gauges have a step, the two faces
corresponds with Maximum and Minimum limits. It is easier
to use system 'B' gauges as compared to System 'A'.
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| DESIGNATION
/ MARKING SYSTEM |
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Prefix
'R' will be used before denoting size of Ring, which
will be always Taper like R1/2"-14 'A'.
Prefix 'Rc' will be used before denoting size of Taper
Plug gauge
like Rc1"-11 'A'.
Prefix 'Rp' will be used before denoting size of Parallel
Plug gauge, like Rp3/4"- 14 'B'.
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