Chapter 2 hydraulic gate Section 1 General 1

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Article 1. Application * •’

This standard is applicable to all hydraulic gates, high pressure valves and trash racks.

Description:

This standard is applicable to hydraulic gates, high pressure valves and trash racks used for water discharge, water intake, sediment flushing and tidal protection at dams for power generation, flood control and irriga­tion, intake weirs (head work), estuary weirs and other waterway structures.

Article 2. Definitions

1. The hydraulic gate in this standard shall mean gate leaves (including bearings), gate guides, an anchorage and gate hoists, the principal com-

’ ponents of which are made of steel materials.

2. The high pressure valves in this standard shall mean valves to be used at 25 m or more waterheads and at least 5 mVs or more flow dis­charges.

Description:

*■ Hydraulic gates and high pressure valves in this standard apply only to those made of steel (including steel castings), but not to other hydrau­lic gates (such as those made of stainless steel, aluminum, Teinforced plas­tic, etc.). Steel stoplogs, however, are covered by this standard.

The types and names of commonly used hydraulic gates are shown below: •

1. Roller Type

Fixed wheel gate (roller gate)

High pressure roller gate

Caterpillar gate (roller mounted gate)

Ring seal gate

Long span wheel gate

Multistage wheel gate

2. Hinged Type

Radial gate

High pressure radial gate

Sector gate

Drum gate

Bottom hinge flap gate

Visor gate

Miter gate

3. Slide Type

Slide gate

High pressure slide gate

Jet flow gate

Ring follower gate

Stoplog

4. Other Types

Rolling gate

Cylinder gate

Sliding gate

The above-mentioned hydraulic gates generally consist of gate leaves, bearings, gate guides, and anchorage and gate hoists. The gate leaf con­sists of a part directly subjected to hydraulic pressure and a part to trans­mit the’load acting on the leaf to the anchorage. The gate guide is a part placed in concrete, where a watertight portion of the hydraulic gate touches the water sealing material. The anchorage is a part to transmit a load from the bearing of the leaf to the concrete, and those other than the hinged type are generally called gate guides.

The gate hoist is a device to open and close the gate leaf. The classifica­tion of the supports, guide and anchorage for the gate leaf is shown in Table 2.2-1.

The high pressure valve to which this standard is applicable has a di­ameter of approximately 600 mm or more. Such high pressure valves gener­ally include the following:

Hollow jet valve

Sleeve valve

Cone valve

Gate valve (sluice valve)

Butterfly valve

Rotary valve

In this standard, the sizes of a small gate, medium gate and large gate are standardized for 3-sided watertight gates as follows: ..

Small sized gate less than 10 m²

Medium sized gate less than 50 m²

Large sized gate more than 50 m²

Table 2.2-1 Classification of Support, Guide and Anchorage for Gate Leaf

—^Qassi fication Name	Bearing	Gate guide	Anchorage
Fixed wheel gate	Portion to transmit the load acting on the leaf to the an­chorage: whfd, wheel pin, rocker beam, bearing, etc.	Main roller rail, front roller rail, side roller rail, seal guide and anchor, etc.
Radial gate / sector gate /.drum gate	Trunnion hub	Side roller rail, seal guide, anchor etc.	Anchorage, trunnion pin, pedestal
Slide gate	Combined use with seal plate	Combined use with seal plate	-
Rolling gate	Rolling tire rack pinion	Seal plates for bot­tom and sides, an­chor, rolling tire rail, rack and anchor
High pressure slide gate, ring follower gate	Combined use with seal plate	Combined use with seal plate	Box-shaped part to accommodate the leaf, built in to the gate guide
Ring seal gate f	Wheel, wheel pin	Seal plate	Same as high pres­sure slide gate, ring. follower gate

Fig. 2.2-2 Long Span Wheel Gate

Hoist

Side guide

Guide (rail)

3 Support

j""* (wheel, wheel pin) ,| Lower leaf

J Support

(wheel, wheel pin) \ Sill

Hoist

\ Sill

rig. 2.2-3 Long Span Double Fig. 2.2-4 Long Span Wheel Gate with Flap

Leaf Wheel Gate ^H

Side guide

Guide (rail)

I Upper leaf

Flow

Fig. 2.2-5 Multistage Long Span Wheel Gate

Support (wheel, spAj " wheel pin)

Support

wheel, wheel pin) Lower leaf

Lower leaf

Hoist

Flow

STkaf ^whed Pⁱⁿ>

Side guide Guide (rail)

Fig. 2.2-6 Double Leaf Wheel Gate (overflow type & non­overflow type)

Lower leaf ~ mt

5 u pport-(wheel, wheel pin)

Hoist

Fig. 2.2-7 Multistage Wheel Gate

Bottom guide

Hoist

Flow

Trash rack

Flow regulating , plate

Upper leaf

Support

(wheel, wheel pin)

Middle leaf

Guide

(rail) Lower leaf

Intake gate

Fig. 2.2-8 Telescope-type Semi- cylindrical Wheel Gate

Fig. 2.2-9 Cateqyillar Gate

Hoist

Hood cover

Hood (casing)

Fig. 2.2-10 Ring Seal Gate

Fig. 2.2-11 Radial Gate

Fig. 2.2-12 High Pressure Radial Gate

Fig. 2.2-13 Sector Gate

(horizontal hinge type)

Fig. 2.2-14 Drum Gate

Fig. 2.2-15 Bottom Hinge Flap Gate

Flow

Guide sheave

(hinge)

Fig. 2.2-16 Visor Gate

Hoist

£ - Hood cover

Fig. 2.2-19 High Pressure Slide Gate

Fig. 2.2-20 Jet Flow Gate

Hoist

Hood cover

77777777777

Flow

Fig. 2.2-21 Ring Follower Gate

LHood. /(casing) /2ZZz

Guide (seal plate)

Fig. 2.2-22 Stoplog

Fig. 2.2-23 Rolling Gate

Fig. 2.2-24 Cylinder Gate

Fig. 2.2-25 Telescope-type Cylinder Gate

Fig. 2.2-26 Hollow Jet Valve

i- i

■ Stilling well

Flow

Valve pipe-

Corner baffle

Fig. 2.2-31 Cone Sleeve Valve

Article 31 Selection of Type and Shape

The type, shape, size and number of hydraulic gates shall be determined in accordance with the installation location, purpose and conditions of use.

Description :

The types and shapes of hydraulic gates can be classified in terms of installation place, purpose and conditions of use as follows:

1. Gates for dams and power generation

1. Spillway gates

Since these gates are normally installed at the overflow portion of a dam and are in full-time use, inspections and repairs are re­stricted, thus requiring attention to this point. In general, a wheel gate and a radial gate are used, but the following gates are used when there is a lot of floating debris:

Sector gate

Drum gate

Bottom hinge flap gate

Gate with flap

2. Conduit gates (orifice gates) and valves

Since these gates are installed inside the dam or downstream of

0

the dam, and since discharge often occurs under high water pres- \ ‘sure, it is necessary to select a gate which has a rigid structure and unfailing operation. +

Many of the operating systems are of the hydraulic type, and generally the following types of gates and valves are used: , Slide gates

High pressure slide gate

Wheel gate

High pressure wheel gate

Caterpillar gate .

Radial gate

High pressure radial gate

Ring follower gate

Ring seal gate

Jet flow gate

Hollow jet valve

Cone valve

Sleeve valve

3. Gates for intakes, silt basins and head tanks

The above gates are installed for intakes, silt basins and head tanks and are used when a silt basin, headrace, head tank, or steel penstock arc inspected or repaired.

Generally a fixed wheel gate or a slide gate is used. However, a high pressure gate, caterpillar gate, or a high pressure radial gate

■ is used when the water head is high.

4. Valves for steel penstocks

In order to regulate the water at both ends of a steel penstock, the following valves are generally used:

Butterfly valve

Gate valve (sluice valve)

Rotary valve

5. Tailrace gate

This gate is installed at a tailrace and is used when a turbine and a draft tube are inspected or repaired and for the purpose of prevent­ing a backward current in floods. The types generally used are as follows:

Slide gate

Fixed wheel gate

6. Sediment flush gate

This gate is in full-time use and is installed to flush the sediments accumulated at a dam, silt basin, headrace, or head tank together with the water. Thus its structure should be rigid and reliable oper­ation should be ensured. The following types of gates are generally used:

Slide gate

Fixed wheel gate

Radial gate

The conduit gate and valve mentioned in (2) above may be used when the water head is high.

6. Surface water withdrawal gate and selective water withdrawal gate

These gates are to intake warm water on the surface or to intake water from any layer, in accordance with fluctuations in the water level. Since they are in full-time use and are submerged in water, they require reliable operation. The types of gates generally used are as follows:

Slide gate

Fixed wheel gate

Multistage wheel gate

Stoplog

Telescope type cylinder gate Multistage semi-cylindrical gate

6. Gates for repair

For a hydraulic gate used to inspect and repair a crest spillway gate, a simple structure with easy transportation is required. There­fore, the following gates are generally used:

In some cases, however, a slide gate or a fixed wheel gate is used to inspect and repair an orifice gate or a sediment slush gate.

2. Gates for intake weirs (head works) and estuary weirs

1. Spillway gate

The span of this gate is longer than that of the crest spillway gate at a dam and generally a fixed wheel gate, bottom hinge flap gate or long span wheel gate is used.

2. Discharge sediment gate

This gate is used to discharge the sediments upstream of the weir and thus the gate is in full-time use. Accordingly a gate of rigid structure and sturdy wear-resistance should be selected. Generally,

a fixed wheel gate or a radial gate is used.

3. Regulating gate

This gate is used to regulate the outlet discharge to downstream and to control the reservoir water level. It is in almost full-time use ¹ . - ■... . 1 during overflows or bottom-discharges. The leaf shape should be good in terms of hydraulic characteristics. A fixed wheel gate, radial ^:Z* gate or bottom hinge flap gate is used and a double leaf wheel gate or a gate with flap is frequently used.

4. Intake gate, silt basin gate arid headrace gate 1

These gates are used when an intake, silt basin or a head-race - is inspected or repaired and when regulating or branching the water flow. Generally, a fixed wheel gate, slide gate or bottom hinge flap gate is used.

5. Fishway gate

This gate is installed at a step-type fishway where the upstream water level fluctuates greatly. A bottom hinge flap gate is frequently used.

6. Navigation lock gate

This gate is used for passage of ships and is frequently operated so a simple structure and reliable operation are required. Generally, a fixed wheel gate, radial gate, miter gate, sector gate or sliding gate is used. In some cases a subgate for discharge is attached.

2. Gate for dikes and sluice way gate

These gates are installed for a sluice way across a dike and are used to prevent a backward current in flood. Generally, one of the follow­ing is used: a fixed wheel gate, a slide gate, a flap gate or a miter gate.

' 4. Tidal gate

This gate is installed around an estuary to prevent the tide from coming-in and to protect against a high tide. It may be in full-time use. Generally, a fixed wheel gate, long span wheel gate, miter gate, visor gate, bottom hinge flap gate, or sliding gate is used.

Section 2 Outline of Design

7. General

Article 4. Design Conditions

A hydraulic gate shall be designed in accordance with the following con­ditions:

1. Safety against predictable load.

2. Sufficient watertightness

3. Easy and reliable operation

4. High durability

5. No harmful vibrations during operation

6. Easy maintenance.

Description :

The above are the basic conditions to be considered in designing the hydraulic gate.

1. In the design of the hydraulic gate, reference should be made to Arti­cle 14. of this Chapter for loads, to Article 15. of this Chapter for load combinations, and to Article 45. and Article 60. of this Chapter for

2 operating loads.

Its structure should be designed so as to minimize secondary stresses generated by such effects as the eccentricity of each member, the rigid­ity of the panel points, sharp changes of cross sections, and the deflec­tion of members by their own weight.

2. In order to keep a hydraulic gate watertight, various shapes of elastic materials are used. Soft rubber is generally used for a low hydraulic pressure and hard rubber for a high hydraulic pressure. Under high pressure, the rubber is pressed against a seal plate. Metal is sometimes used as a seal material.

3. When a hydraulic gate is operated, its own weight, friction force, up­lift force, and down-pull force are at work, so the gate should be equipped with a hoisting device having sufficient capability, thus en­suring easy and reliable operation.

4. Since a hydraulic gate is used for long time, it is necessary to make a thorough investigation into the water quality at the site in advance to consider corrosion and wear in the design of the gate leaf, gate guide, anchorage and hoisting device.

5. In designing a hydraulic gate to be operated under high pressure, at­tention should be paid to the fact that the shapes of the gate leaf and

guide and the air supply to the backside of the gate are related to vibration. . • •

6. Consideration should be given to ensure that easy operation and main­tenance are provided for the hydraulic gate. . .

Article 5. Selection of Type of Hoisting Device

In selecting the type of hoisting device, careful consideration should be given to the type, size, purpose and frequency of use, and to the place of installation of the hydraulic gate.

Description:

The classification of hoisting devices is listed in Table 2.5-1.

Table 2.5-1 Type of hoisting device

Gate type	Purpose		Type of hoisting device
			Electric *			Hydraulic
			Wirerope winding type	Screw ’spindle type	(>' * Rack gear - typ« .	Cylinder type	Cylinder .wire type	hydraulic motor wirerope type
Fixed wheel gate	Dam 4 power generation		O	O	X	A	A	O
	Weir		O	A	A	A	A	O
	Sluice way	Large-size gate	O	X	X	A	A	O
		Medium-size gale	O	A	A	A	A	O
		Small-size gate	O	O	O	A	A	A
	Navigation lock		O	A	A	X	A	0
High pressure roller gate	Dam & power generation (main gate)		A	A	X	o	X	X
	Dam 4 power generation (guard gale)		0	X	X	A	X	A
	Intake		O	A	X	A	X	A
Radial gate	Dam 4 power generation		O	X	X	A	A	O
High pressure radial gale	Dam 4 power generation		A	A	X	O	X	X
Slide gate	Sluice way	Medium-size gale	A	o	o	A	A	A
		Small-size gate	X	o	o	A	x;	X
High pressure slide gate (ring follower gate in­clusive)	Bottom hinge flap gate		X	o	X	O	X	X
Dam & power generation	Weir		o	A	X	O	o	A
Miter gate, sector gate (vertical hinge), swing gate	Navigation lock		o	A	A	o	o	X

Note O ... Operating system suitable'for use

A .. Operating system suitable for use in some cases x .. Operating system not suitable for use

1. Wirerope winding type

This type can be widely used for medium-size and large-size gates.

2. Screw spindle type and rack gear type

These types are suitable fpr small-size gates.

It is better not to use this type for a hydraulic gate of large lifting height and large size because of difficulties in terms of structure.

3. Hydraulic cylinder type

This type is widely used for high pressure gates. It is advantageous when the opening of the gate leaf must be strictly adjusted or when the hoisting device should be installed in a narrow space, but extra cost is required for the replacement of oil and maintenance. Note that in some cases, the reaction of the operating force may not be sustained at the supports of the hydraulic cylinder.

4. Hydraulic cylinder wirerope type

This type is used when items (1) and (2) above are difficult to use,

1. e. when a hoist is installed inside the gate leaf or gate arm because the installation area for the hoist is extremely small.

In choosing this type, frequency of use and maintenance should be thoroughly studied. It is better not to use this type for a hydraulic gate of large lifting height and large load because of difficulties in terms of structure.

5. Hydraulic motor wirerope type

When multiple hydraulic gates are installed, they can be operated by switching a valve through one hydraulic pump. This type is con­venient for changing operating speeds steplessly.

Article 6. Power Equipment for Gate Operating

Power equipment capable of operating the gates any time without fail shall be provided for hydraulic gates. For small size gates, however, manual equipment may be installed.

Description'. ;

* i

In order to ensure rapid operation, power equipment for this purpose should be provided for hydraulic gates. Generally, a motor is used, but an internal combustion engine may be used for a small dam, such as an intake dam. In the above case, the type and amount of power equipment should be determined by taking maintainability, frequency of flood oc­currence and the speed at which the water-level rises into account.

For a hydraulic gate to be operated by means of buoyancy or counter­

weight, it is necessary to take some measures against the vibration of the gate leaf caused by the buoyancy.

Measures should also be taken so that a gate can be operated in an emer- gency or for inspection.

As for the hoisting capability of manual equipment, it is common to . assume that manpower is 10 kgf or less and that the gate can be lifted to the required height within about 30 minutes. Thus, compact power equipment is required for the hydraulic gate if this target cannot be met manually.

Article 7. Operating Speed

The operating speed of a hydraulic gate shall be in accordance with the purpose of its use.

Description:

The operating speed of a hydraulic gate is usually taken as 0.3 to 0.5 m/min, taking account of upstream and downstream effects caused by the discharging of water. But when the operating speed is-slowed by automatic control or for some other purpose, about 0.1 m/min is taken. When the speed is increased at a navigation lock for example, 1.0 to 5.0 m/min is taken.

When controlling flow at a bottom hinge flap gate, the closing or open­ing time is usually taken as 10 to 20 minutes.

Approximately 0.05 to 0.1 m/min is taken for high pressure valves.

Article 8. Lifting Height

The lifting height of a hydraulic gate shall be determined so as to be safe against the downflowing water after the gate is lifted.

Description :

For a spillway gate, the clearance between the bottom of the gate when it is lifted up and the water surface should be determined by considering the shapes and sizes of drifting debris during a Hood. However, at least 1.5 m is required for clearance between the bottom of the gate when it is lifted up and the overflow surface at the time the flood water for the dam design is discharged. A clearance of at least 1.0 m suffices for an overflow depth of 2.5 m or less.

Article 9. Auxiliary Power Equipment

1. Auxiliary power equipment for operating the gate shall be provided

for an important hydraulic gate.

2. Auxiliary power equipment shall be capable of operating a hydraulic gate promptly without fail, even if the normal power service is inter­rupted.

Description :

1. It is necessary to provide auxiliary power equipment for important hydraulic gates in order to ensure that there is no difficulty in operat­ing the gate even if a power failure takes place due to failures in trans­mission lines during a flood. In some cases, however, when no serious damage can be expected either upstream and downstream of a hydraulic gate, or when a bottom hinge flap gate uses the gate’s buoyancy, aux­iliary power equipment is not necessary.

2. A generator powered by an internal combustion engine is generally used as the auxiliary power equipment. In some cases, a stand-by power source may be supplied from a directly branched transmission and dis­tribution line but, in these cases, a power source should be supplied from another transmission system which should not be interrupted at the same time as the normal service line. It is necessary for the standby power source to unfailingly perform its function as auxiliary power equipment.

There have been examples in which an internal combustion engine used as the auxiliary power equipment was directly connected to a hydraulic gate.

Article 10. Materials of Hydraulic Gate

The materials used for a hydraulic gate shall be equivalent or superior to those listed in Table 2.10-1.

Table 2.10-1 Type and Application of Materials

	Name	Type	Symbol :	Place used
1	Rolled steel for general	JIS G3I01	SS41 SS/\5t)	Leaf, guide, leaf support,
	structures	(1976)		anchorage, hoist base; bolt
2	Steel bars for rivets	JIS G31M (1976)	SV34 SV41 l__ . . _ ........	Rivets
3	Carbon steel and molyb­denum alloy steel plates for boilers and other pressure vessels	JIS G31O3	. SB42 SB46 SB49	Oil hydraulic cylinder
4	Rolled steel for welded structure	JIS G3106 (1977)	j SM41A (B or C) j SM50A (B) 1 SM50YA (B) 1 SM53B (C) SM58	Leaf, guide, leaf support, anchorage

Name		Type		Symbol		Place used
5	Steel bars for concrete reinforcement		JIS G3112		SR24 SD24 SD30 SD35		Anchor
6	Hot rolled atmospheric corrosion resisting steel for welded structures		JIS G3114 (1977)		SMA41A (13 or C) SMA50A (B or C) SMA58 •		Leaf, guide, leaf ’support, anchorage
7	Cold finished carbon and alloy steel bars		JIS G3123 (1979)		SGD30-D SGD41-D		Shaft, boll
8	Carbon steel forgings for general use		JIS 03201 (1978)		SF40A SF45A SF50A SF55A SF60A		Major diameter of gear shaft, trunnion hub, flange
9	Carbon steel tubes for general structure purpose		JIS G3444 (1977)		STK30 STK41		Leaf, protective pipe, handrail, shaft for load transmission
10	Carbon steel pipes for ordinary pipings		JIS G3452 (1978)		SGP		Low pressure oil hydraulic » pipe, air pipe, handrail
11	Carbon steel pipes for pressure service		JIS G3454 (1978)		STPG38 STPG42		High pressure oil hydraulic pipe, feed & drainage pipe oil hydraulic cylinder
12	Carbon steel pipes for high pressure service		JIS G3455 (1978)		STS38 STS42
13	Stainless steel pipes		JIS G3459 (1978)		SUS304TP SUS316TP		Leaf, protective pipe, shaft for load transmission
14	Wireropc		JIS G3525 (1977)		6;6 x 37 ll;6 x W (19) 13;6 x Fi (29) 21 ;6 x WS (36)		Hoisting cable
15 if	Steel bar for pre-stressed concrete		JIS G3109		SBPR 80/ 95 lSBPR 80/105 SBPR 95/110 SBPR 95/120 SBPR110/125 SBPR110/135		Anchor material for pre­stressed concrete i i
16	Uncoalcd stress-relieved steel wire and strand for pre-stressed concrete		JIS G3536 (1981)		SWPR1 SWPR2
17	Carbon steel for machine structural use		JIS G4051 (1979)		S25C S30C S35C S40C S45C		Wheel, gear, gear shaft, transmission shaft, anchor, bolt
18	Nickel chromium steels		JIS G4102 (1979)		SNC236 SNC631 SNC836		Gear, shaft, bolt
19	Nickel chromium molybdenum steels		JIS G4103 (1979)		SNCM439 SNCM630		1 High strength boll i
20	Chromium steels		JIS G4104 (1979)		SCr440		’1
21	Chromium molybdenum steels		JIS G4105 (1979)		SCM430 SCM432 SCM435 SCM440 SCM445		Gear, shaft, boh i 1

	Name	Type	Symbol	Place used
22	Stainless steel bars	JIS G4303 (1981)	SUS3O4 SUS4O3 SUS410 SUS420J1 (J2)	Wheel shaft, sheave shaft, piston stem
23	Hol rolled stainless steel sheets and plates	JIS G4304 (1981)	SUS3O4 SUS316 SUS403 SUS410	Seal plate and sliding plate for leaf and guide, tread of a roller rail.
24	Cold rolled stainless steel sheets and plates	JIS G43O5 (1981)	US304 SUS316 SUS4O3 SUS410
25	Hot rolled stainless steel strips	JIS G43O6 (1981)	SUS3O4 SUS316
26	Cold rolled stainless steel strips	JIS G4307 (1981)	SUS304 SUS316 SUS329J1 SUS410 SUS420J2
27	Stainless-dad steel	JIS G360I	SS (SM or SMA) + SUS	Leaf, guide, seal plate
28	Carbon steel castings	JIS G5101 (1978)	SC37 SC42 SC46 SC49	Leaf, casing, leaf support, gear, roller, parts for toisl, hydraulic cylinder, sheave, drum
29	Steel castings for welded structure'	JIS G5102	SCW42 SCW49 SCW56 SCW63
30	High tensile strength carbon steel castings and low alloy steel castings for structural purposes	JIS G5111 (1978)	SCMnlB SCMn2B SCMn3B SCMn5B SCMnCr2B SCMnCr3B SCMnCr4B SCC3B SCC5B SCNCrM2B	vfain wheel, large gear
31	Stainless steel castings '	JIS G5121 (1980)	SCS2 SCSI2 SCS22	Main wheel, leaf bearing
32	Gray iron castings	JIS G55O1 (1976)	FC20 FC25	Parts for hoist, sheave
33	Spheroidal-graphite iron castings	JIS G55O2 (1975)	FCD45 FCD50	Piston, sheave
34	Copper and copper-alloy sheets, plates, strip and cold sheets	JIS H3100 (1981)	C2600P C2680P C2720P C2801P	Sliding plate
35	High strength brass castings	JIS H5102	HBsC4	Pushing
36	Bronze castings	JIS H5111 (1979)	BC2 BC3 BC6	Sliding plate, seal plate, bushings
37	Phosphorus bronze castings	JIS H5113 (1979)	PBC2 PBC2B PBC3B	Bushings, worm wheel
38	Aluminum bronze castings	JIS H5II4	A/BC2 A/BC3	Corrosion-resistant bushings
39	Leaded tin bronze castings *	JIS H5I15 (1979)	LBC2 LBC3	Sliding plate, bushings
40	Rails	JIS El JOI	30A 37A 40N 50PS 5ON6O	Rails
41	Solid rolled carbon steel wheels for railway roll­ing stock	JIS E5402	SSW-R1 (2 or 3) SSW-Q1S (2S or 3S) SSW-Q1R (2R or 3R)	Main wheel

Description:

1. This Article is applicable to the materials used for high pressure valves and trash racks.

2. The gate manufacturer should run material tests before actual use to ensure that the material satisfies JIS specifications. If the material has been cleared by the material test results made by the steel factory, the gate manufacturer may substitute those results for his own test.

It is standardized that steel types should be selected in relation to plate thicknesses, based on Table 2.10-2.

Table 2.10-2 Steel Type Selection Standard according to Plate Thickness

'^\Plate thickness Steel type	8 16 22 25 32 38 50
SS41							•
SM41A
SM41B							•
SM41C
SM50A					i		•
SM50B

Notes 1) It is desirable to use killed steel for the thick plate of welded structures.

2. Materials with good toughness in cold weather should be cho­sen when temperatures go extremely low.

3. Atmospheric corrosion-resistant steel for welded structures (SMA) should be equivalent to the steel for welded structures (SM).

4. Unnecessary use of numerous kinds of steels for the same gate should be avoided.

5. As the impact load on a hydraulic gate is smaller than that on a bridge, even if the thickness exceeds that given in the Table, it can be used, provided that careful manufacturing work is done by taking care in weldability.

3. For times when use of high strength bolts should be applied, please see Chapter 5, Section 3 High Strength Bolt Joint.

Article 11. Material Test

1. Inspections, tests and reports of the materials not specified in Table 2.10-1, Article 10. of this Chapter shall be in accordance with the Gen­eral Rules for Inspection of Steel (JIS G0303) and General Rules for- Inspection of Non-ferrous Materials (JIS H0321), unless otherwise: specified in the specifications of each material.

2. When using extremely thick or special materials, their weldability and other characteristics shall be tested.

Description:

1. When using a material not described in Table 2.10-1, and if this material belongs to JIS, it must be ensured that the material satisfies the stan­dards concerned. Materials not covered by JIS should be inspected and tested based on the General Rules for Inspection of Steels, and the results required should be confirmed.

2. When an extremely thick or special material is used, it is necessary to - test other problematic points in addition to the general test included in the aforementioned General Rules for Inspection of Steel because other problems such as workability, weldability and manufacture may • arise.

For each steel material, tests to be run, but not specified in JIS, are . as follows:

Base Metal ... workability test, heat-affect test, brittleness test, magnetic particle lest (large size steel castings and forgings)

Weld zone ... hardness test, cracking lest, joint strength test, brit­tleness test

Welding

material workability test

Corrosion tests and structural tests are to be run in addition to the above tests.