4 snubber and rigid strut

Snubber andRigid Strut

Size No.Rated Load

(kN)


Size

Symbol of Rear Bracket

-BSN 6

03

06

1

3

6

10

16

25

40

60

100

3

6

10

30

60

100

160

250

400

600

1,000

Whenever unplanned dynamic loads occur, the dynamic duty components havethe job of protecting the piping or other components affected from anydamage.

Unwanted abrupt movement of the components in the system can be causedby:1) Internal excitation ; pressure shocks from valve operation, water hammer,

pipe breakage, boiler event2) External excitation ; wind load, seismic events, aircraft impact, explosion

Snubber is a device developed to protect high pressure/temperature pipingsystem in power plants and various types of industrial plants. It functions torestrain undesirable displacement of piping system or components when it isoscillate due to seismic or other type dynamic load, while it allows their freemovement during the normal operating mode. On the other hand, rigid strut sustains the dynamic load, but do not allow axialmovement. However, as it has angular bearings, limited angular movement ispermitted.For the dynamic duty components, the dynamic loads are grouped as follows ;

1.0 REAR BRACKET1.1 Type Designation

1.2 Dimensions

Note) Special order requiredfor Size 40, 60 100

Rated Load for DynamicDuty Components


Size

Configuration(S : Short, L : Long)

Symbol of Rigid Strut

--RS S 062.0 RIGID STRUT2.1 Type Designation

Type S ; installation length adjustable at one end in field(short type, ± 35(mm))Type L ; installation length adjustable at both ends in field(long type, ± 75(mm))

2.2 DimensionsType S

Type L

3.0 SNUBBER AND SNUBBER EXTENSION3.1 Type designation

Snubber Snubber Extension

Total Stroke for Snubber(mm)100(mm), 160(mm), 250(mm)- Standard Type310(mm), 400(mm), 460(mm) and 510(mm) - Extra stroke ; available on request

Combination of total stroke and design displacement

○ : Optimum, △ : Usable, X : Not Usable

Assembly Type for SnubberType FA : with shortest attachment for a limited installation lengthType EA : with extension attachment for a long installation lengthFor Type EA, snubber extension will be required to enlarge the C-C dimension

3.2 Feature

Fig. 3.1 show the schematic diagram and main items of the SnubberSeveral features are described as follows;(1) Reliable hydraulic system including precise valve mechanism assures stable and symmetrical performance

in both loading directions.(2) Self-contained oil reservoir eliminates fluid leakage from sealed connections.(3) High durability of seal materials assures longer service duration without frequent maintenance work.(4) Well-engineered construction simplifies disassembling and re-assembling of the unit, assuring easier

maintenance works.(5) Installable in a limited space because of a plain cylindrical contour.(6) Filled with thoroughly verified genuine hydraulic fluid.(7) Easy-to-read stroke indicator.


Total Stroke Length(mm)

Assembly Type(EA, FA)

Size

Symbol of Hydraulic Snubber

SNA -- -16 EA 160

Length(mm)

Size

Symbol of Snubber Extension

--SNP 16 1000

Total stroke(mm)Designdisplacement

50 or less

51-110

111-200

201-260

100

○

X

X

X

160

△

○

X

X

250

△

△

○

X

310

△

△

△

○


Caution : Without special comments of the Customer, the snubber will be preset at the shop as follows;● Preset at 25(mm) if snubber were extended during hot state, ● Preset at [total stroke-25](mm) if snubber were retracted during hot state.

3.3 CharteristicsMinimum Spring Rate(kg/mm) per load and stroke Design Parameters

SNA - 03

SNA - 06

SNA - 1

SNA - 3

SNA - 6

SNA - 10

SNA - 16

SNA - 25

Stroke(mm)

Type

Design Parameter

Drag force

Bleed Rate

Lock-up Rate

Frequency Range

Pressure Capacity

Perm. Cycle under rated load

Temperature

Radiant Limit

Recommended Maintenance

Angular Offset

Criteria

2% of the rated load, or 50(kg),

whichever is greater

0.5(mm/sec)

1~ 4(mm/sec)

1~ 33(Hz)

1.5 times of the rated load

20,000(cycles)

-15 ~ 60(℃)

1×108(TEKOHR 200 Fluid)

Once every 10 years

Max. 15 。

100

250

450

650

1,500

3,000

5,000

7,000

8,000

160/250

150

300

450

1,000

2,000

3,000

4,500

6,500

Fig. 3.1 Schematic Diagram and Main Items

Item NameHolderCasingCylinder CoverCylinder TubeRod CoverPistonPiston RodTie RodAccumulatorCasing CoverTravel IndicatorCanvas Cover

Part No.123456789101112


Note 1) A2 : fully contracted length

3.4 DimensionsType FA


Type EA

Note 1) Length at middle position


k

Type SNP

4 snubber and rigid strut

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