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パラレルスライドゲートバルブ
パラレルスライドゲートバルブは位置決めでシールします。スプリングが2枚の平行な閉止体を押し合わせて低圧着座させ、その後は管路圧力の上昇が両者をシートに押し付けるため、流体圧力が高まるほどシール力が増します。蒸気や給水管など高圧・高温用途を狙った自己増力密封方式です。範囲はNPS 2"～88"（DN50～DN2200）、Class 300～4500（PN25～PN760）、ボディは炭素鋼・合金鋼・デュプレックスステンレス鋼、端接続はRF・BW・RTJ、操作は手動・空圧・電動・油圧です。設計上の利点は3つ。平面シートを滑る平行ディスクは熱停止後にウェッジが噛み込むような熱着座を起こさないため、熱サイクルの多い高温蒸気ラインはまさにこの故障様式を排除するためにこの形式を採用します。くさび機構がないため操作トルクが低く、アクチュエータ選定が容易です。高クラスではプレッシャーシールボンネットが管路圧力と同じ方向にシート密封を補強し、密封力は差圧とともに増大します（ディスクスプリングや内部スペーサが低差圧側の実用密封限界を決めます）。本弁は厳密な開閉弁です。中間開度で保持すると平面シートが侵食され、高周波のディスクチャッターが発生するため流量制御には別途調整弁が必要で、固形物の滞留や配管歪みによるシート変位はディスクの着座を妨げます。最終閉止前にラインをフラッシュし、配管の芯出しを維持してください。保守は工場向きです。特殊工具なしで分解、ディスクスプリング交換、シート面のラッピング・再生、グランド圧の管理、ステムねじの給脂、常時開/閉のシートへの堆積防止のための定期開閉を実施します。垂直方向の空間があれば位置表示が有効な昇降ステム、狭所・地下には非昇降ステムを選びます。密閉性はAPI 598（シェル、閉止、バックシート）で証明し、欧州系枠組みはISO 5208 / EN 12266-1です。API 600はボルト締結ボンネットのプロセス遮断弁を規定し、API 6Dは火災試験、サワーサービス、サイクル、キャビティ自動圧力開放などAPI 600枠にない配管特有の要件を追加します。選定は蒸気条件に対するクラス、媒体に対するボディ合金、配管仕様に対する端接続で決まります。
次のファミリーに属する： ゲートバルブ ファミリー
最終更新： 2026-11
ファミリー仕様
| Nominal valve connection size | NPS 2"~88"(DN50~DN2200) |
|---|---|
| Pressure class / nominal rating designation | Class 300~4500（PN25~PN760） |
| Pressure class / nominal rating designation | 300~4500（PN25~PN760） |
| Valve body material | Carbon steel, Alloy steel, Duplex stainless steel |
| End connection types | RF, BW, RTJ |
| Operation / closure mode | Manual, Pneumatic, Electric, Hydraulic |
| applications | High pressure and high temperature services such as steam and feedwater |
| selection thermal binding elimination vs wedge | Parallel slide gate valves avoid thermal binding because the two discs slide parallel to flat seats instead of being forced between inclined seats, so body contraction during shutdown cannot wedge the closure member tight. This makes the design the usual choice for high-temperature steam lines that undergo frequent thermal cycles. |
| selection pressure assisted sealing low deltap basis | Sealing force comes from line pressure acting on the downstream disc, so seat tightness improves as differential pressure rises. At low pressure the disc springs or internal spreaders alone provide the baseline seat contact, which sets the practical low-differential-pressure sealing limit of the design. |
| selection no wedging seizure and torque | Because the discs do not wedge, opening and closing torque stays low and there is no wedging action to seize the valve after thermal expansion. This reduces actuator sizing and lowers seat wear over repeated operating cycles. |
| selection pressure seal bonnet self energizing | For high-pressure classes the bonnet is typically of pressure-seal type: internal pressure forces the gasket more tightly into its seat, so bonnet sealing improves as pressure rises. This matches the self-reinforcing behavior of the parallel-disc seat seal. |
| selection hp steam water isolation positioning | The parallel slide gate valve is an established valve type for high-pressure steam and high-pressure water isolation duty, offered in ratings from ANSI 150 to ANSI 1500 with tight shut-off obtained from line pressure rather than mechanical wedging. |
| selection catalog size class envelope example | A typical commercial parallel slide gate valve envelope runs from small sizes up to DN900, in ANSI class 150 to 600 with flanged or butt-welded ends. Wider class ranges are offered by power-plant specialists, so class availability must be confirmed per manufacturer. |
| failure throttling chatter seat erosion | Parallel slide gate valves are on-off isolation devices only. Holding the valve partially open for throttling produces turbulence across the nearly closed flat seats, eroding the seat faces and driving high-frequency disc chatter, so a separate regulating valve is required where flow control is needed. |
| failure trapped solids seat leakage | The flat, closely finished parallel seats are vulnerable to debris: suspended solids trapped between the faces hold the discs off the seat and cause leakage, and piping loads that distort the seats have the same effect. Line flushing before final closure and correct piping alignment are the preventive measures. |
| failure thermal binding wedge mechanism contrast | Thermal binding, the classic wedge-gate failure after a hot shutdown, occurs when the cooling body contracts and clamps the wedge between the seats, seizing the valve or buckling the stem. The parallel-disc design is selected precisely to remove this failure mode from high-temperature service. |
| installation routine maintenance and exercise | Routine care consists of checking gland packing compression, lubricating the stem threads, and periodically cycling (exercising) the valve so deposits cannot build up on the seats and disc edges - an important regime for valves that normally stand open or closed for long periods. |
| installation seat refurbishment workshop tooling | The valve can be disassembled for inspection without special equipment: seat faces can be examined, internal disc springs replaced, and sealing surfaces restored with standard workshop tooling, which keeps lapping or seat refurbishment practical in normal maintenance. |
| installation stem choice vs vertical clearance | Rising-stem versions give clear visual open/closed position indication but need vertical space above the valve; non-rising-stem versions keep the stem height fixed and suit confined installations such as underground vaults and cramped pipe racks, at the cost of less obvious position indication. |
| standards api598 closure testing reference | Seat (closure) tightness for steel gate valves of this family is generally proven per API 598 as referenced by the valve specification, with shell, closure and, where fitted, backseat tests. ISO 5208 / EN 12266-1 rate classes are the equivalent European acceptance frame. |
| standards api600 vs api6d scope | API 600 governs bolted-bonnet steel gate valves for refinery and process isolation, while API 6D is the pipeline-valve standard covering gate valves for transportation systems and adds pipeline-specific requirements such as fire testing, sour service and operational cycling. Project specifications may require one or both. |
| standards api6d cavity pressure relief | Where a gate valve is built to API 6D for pipeline service, the body cavity must be able to relieve trapped overpressure automatically in addition to the normal shell and seat tests - a requirement not present in basic API 600 process-isolation valves. |
| peer size range severe service psg | 4 – 36" |
| peer pressure class severe service psg | ASME / ANSI Class 150 – 4500 |
| peer body materials severe service psg | Carbon steel (A216 WCB) – standard Alloy steel (A217 WC9, A217 C12A) – standard Stainless steel (A351 CF8M) – standard |
| peer compliance nuclear silver psg | ASME B16.34 PED Nuclear ASME III Class 1, 2 and 3 Nuclear Safety Related – 10CFR50 Appendix B SIL |
| peer end connection default psg | Buttweld – standard Other end connections available upon request |
| psg bidirectional zero leakage shutoff | Bi-directional, zero-leakage shutoff |
| psg disc seat carbide overlay | The valve discs and seats have been overlaid with the same carbide overlay (68-70 RC) |
| psg seat lapping vacuum tight | and are lapped to achieve a bubble-tight seal under all pressure conditions, including vacuum. |
| psg web guide parallel discs | The web guide (which is also carbide overlayed) ensures the discs are kept parallel, whether the valve is in the open or closed position. |
| psg wear honing not galling | As the valve is cycled under differential pressure, the extremely hard surfaces continually hone and polish each other instead of scratching and galling. |
| psg pressure seal bonnet graphite composite | The pressure seal bonnet has been designed with a graphite composite seal. |
| psg bonnet bolting cold preload | The bonnet has sufficient mechanical bolting to ensure the seal does not relax during periods when the system is not pressurized. |
| psg stem gland hardfaced polished | The stem and gland are hardfaced and polished. |
| psg backseat chrome carbide | The back seat is coated with chrome carbide (typical hardness 68-70 RC) and polished to achieve a bubble tight seal. |
| peer size range double disc psg | NPS 2 1/2 to 24 DN 65 to 600 |
| peer pressure class double disc psg | 150 to 1500 PN 25 to 260 |
| peer seating material double disc psg | Seating Material: Metal |
| double disc design service envelope | this exclusive disk and wedge design resists effects of extreme temperatures, gross thermal transients, high and low differential pressures, and dual-phase fluids. |
| double disc bonnet internal access | Increased plant and personnel safety is made possible by bonnet design, allowing easy access to valve internals while minimizing radiation exposure |
| peer standards nuclear double disc psg | ASME B16.34 ASME Section III |
| peer actuation configs double disc psg | Motor Actuated Motor Operator Hydraulic Actuated Hydraulic Operator |
| psg disc cooldown no stress | There is no mechanical stress exerted between the discs or problems associated with the cooldown of the fluid. |
| sealing principle | Positional seal, Line pressure as sealing force |
| special features | Spring between the two closure members provides an initial seal during low pressure conditions, Higher medium pressure creates the primary seal, the higher the medium pressure the better the sealing performance |
範囲と出所の注記
| type level parameters | A Chinese vendor page under the same English name lists Flexible/Solid Wedge materials and 1.0-2.5 MPa water/sewage duty, while OEM references position the parallel slide type as high-pressure steam/water isolation up to ANSI 1500 - the vendor page appears to describe a low-pressure slide-gate family; its parameters are product-specific, not type-level. |
|---|---|
| sealing direction framing differs by construction | Sealing-direction framing differs by construction: one source characterizes API 600 gate valves as unidirectional sealing relying on bolted-bonnet pre-load, while parallel-slide references describe line-pressure-assisted bidirectional sealing - the framings reflect different gate constructions under the standards, not one sealing rule. |
| temperature range | Temperature envelope differs materially between catalog sources (-196 to 593 C on one catalog versus -29 to 425 C on another); the tenant entry quotes no single type-level envelope and per-material limits must be confirmed per manufacturer. |
注文と書類
書類
お問い合わせの際に必要な書類セットをお知らせください——この型番仕様の典型的な項目（材質証明書、記載の検査規格に基づく試験報告書、寸法図）は、見積時に確認のうえ供給されます。
お見積り
見積可能なお問い合わせには次の事項をご記入ください：呼び径と圧力レーティング、ボディ・シート材質の希望、接続方式、操作方式、温度を含む使用流体。このページの典型値はベンチマーク参考範囲です。拘束力のある値は見積時に確定します。
サンプルと供給
供給条件、発注数量、納期は注文ごとに協議します——お問い合わせの際に納入国と希望スケジュールをお知らせください。
保管と輸送
バルブはシート・シールを紫外線、オゾン、変形から保護して保管し、据付まで端面保護カバーを取り付けたままにしてください。エラストマーまたは PTFE シートの仕様では、屋外での長期保管を避けてください——シート材料は直射日光と凍結条件で最も劣化が早くなります。
よくある質問
パラレルスライドゲートバルブの見積依頼には何を含めるべきですか？
適用規格とクラス、呼びサイズ、ボディおよびシート材、使用媒体と温度、納入先——欠落している項目は見積の過程で確認します。
パラレルスライドゲートバルブにはどのサイズと圧力等級がありますか？
このバルブの検証済みサイズと圧力等級範囲はまだ本ページに掲載されていません——お客様の使用条件に適したサイズと圧力等級は見積の過程でご提案し、確認します。使用条件を問い合わせに添えていただければ、選定結果を見積書に記載します。
パラレルスライドゲートバルブにはどのボディ材質がありますか？
このバルブの検証済みボディ材質範囲はまだ本ページに掲載されていません——お客様の使用条件に適したボディ材質は見積の過程でご提案し、確認します。使用条件を問い合わせに添えていただければ、選定結果を見積書に記載します。
パラレルスライドゲートバルブ の見積依頼
こちらからご要望をご提出ください——見積に直結するお問い合わせには、適用規格とクラス、口径、材質、流体、温度、納入先をご記入ください.
お客様の情報の取り扱いについては、プライバシー通知をご覧ください。