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BOP系統案例研究 --
高壓高精度變送器
產品：H455T2-33-P15-A1型壓力變送器
說明：采用薄膜技術的高壓H455型號，30K psi范圍，HiP HF4或AE FC250等效工藝連接，HART 通信協議
問題：
防噴器（BOP）的原始設備制造商必須遵守API規范Q1中規定的內部質量標準，此外，許多制造商還制定了符合API S-53建議的重新認證計劃，以翻新舊設備。Barksdale與一家BOP原始設備制造商（OEM）合作，該制造商致力于提供持續改進的質量管理體系，強調缺陷預防和測試產品的一致性，減少過程中的可變性和浪費。客戶的校準計劃要求對所有用于測試BOP系統的壓力變送器進行90天周期的校準，目標是將校準精度保持在0.25%以內。如果無法保持準確度，則需要重新測試BOP系統，而OEM的成本非常高。OEM使用0.25%精度、30000 psi和10000 psi范圍的4-20mA模擬變送器，使用箔應變計技術和電位計進行零點和量程微調。電位計是OEM在發現其超出精度規格時調整校準的重要功能。然而，電位計隨溫度和振動而漂移，這需要使用glyptol來防止旋轉。OEM為每個變送器遵循嚴格的多點校準程序，如果需要調整電位計進行零點或量程微調，則可能需要四小時，甚至八小時。當變送器不能再在規范范圍內校準時，將其丟棄。雖然原始設備制造商維護了一些備件，但替換變送器的供應商提供的交貨期為14-22周。
解決方案：
經過多年的努力，Barksdale的新BiT產品系列為發射機找到了另一個能夠在測試環境中生存并保持精度的來源，從而迎接了挑戰。Barksdale的智能變送器的薄膜技術設計提供了更好的精度，可降至0.1%，并在高循環工業應用中證明了長期穩定性，可超過10億次循環。此外，HART。通信協議為幾個問題提供了一些顯著的優點，并減少了定位和跟蹤需要校準的發射機所花費的時間。
結果：
OEM對Barksdale變送器進行了疲勞、沖擊載荷和低溫/高溫測試，隨后進行了嚴格的校準過程，以確保校準得以維持。更高的精度提供了更多的裕度，以保持其最小0.25%的精度，并且預期更好的長期穩定性將增加微調之間的時間。HART協議允許數字零點微調和重新調整量程，從而消除了對隨溫度和振動漂移的電位計的需求，從而進一步提高了變送器的穩定性。BiT HART變送器量程調整功能包括10:1的調低，這允許OEM儲存一個可從30000 psi或10000 psi范圍重新配置的部件。HART協議的其他優點包括獨特的設備ID和創建自定義標簽以識別每個變送器的能力，以幫助跟蹤和識別系統中變送器的物理位置。OEM能夠在其現有數據采集系統中添加一個模塊，通過HART協議進行通信，并從控制系統中識別安裝在每個測試間中的變送器。
圖1。顯示帶有數字零點微調和重新調整范圍的BiT（左），以及帶有電位計的競爭對手單元，用于手動調整零點和量程微調（右下）。電位計隨溫度和振動而漂移，需要glyptal將電位計鎖定到位（右上）。
圖2:顯示防噴器測試間。測試包括在壓力和沖擊載荷下對橡膠密封插件進行高溫和低溫測試，在大型陸上防噴器上，包括立即施加0至7500 psi的壓力。
Barksdale成立于1949年，是高度工程化控制產品的領先制造商。作為Crane Co.的子公司，Barksdale在儀表領域擁有領先的品牌地位，專注于通用工業、石油天然氣和運輸終端市場。憑借專有技術，Barksdale的閥門、調節器、壓力開關、電子設備和速度儀表產品在苛刻的應用中為自己創造了一席之地。
Barksdale是防噴器閥門和調節器的領先供應商，還提供可用于滿足API RP 53防噴器現場測試要求的危險區域BiT變送器。Barksdale保持流行車型的庫存，以將交付周期縮短至最多4周。
BOP System Case Study
High pressure, high accuracy transmitter
Product: Model H455T2-33-P15-A1 Pressure Transmitter
Description: High Pressure H455 model with thin-film technology, 30K psi range with HiP HF4 or AE FC250 equivalent process connection, and HART? communication protocol
Problem:
Original equipment manufacturers of Blowout Preventer (BOP) are required to follow their internal quality standards per API specification Q1, in addition many have recertification programs that follow API S-53 recommendations to refurbish used equipment. Barksdale collaborated with a BOP original equipment manufacturer (OEM) that is committed to a quality management system that provides continuous improvement, emphasizing defect prevention and conformity of the product being tested with reduction of variability and waste in the process. The customer’s calibration program requires a 90-day cycle of all pressure transmitters used for testing their BOP systems with the goal of maintaining calibration within 0.25% accuracy. Failure to maintain accuracy requires retesting of BOP systems at a very high cost to the OEM. The OEM was using 0.25% accuracy, 30,000 psi and 10,000 psi range 4-20mA analog transmitters using foil strain gage technology with potentiometers for Zero and Span trim. The potentiometers were an important feature to the OEM to make adjustments to the calibration when they were found to be out of accuracy specification. However, potentiometers drift with temperature and vibration which requires application of glyptol to prevent rotation. The OEM follows a rigorous multi-point calibration procedure for each transmitter that can take up to four hours and potentially up to eight hours if any adjustment of the potentiometers for zero or span trim is required. When the transmitter can no longer be calibrated within specification, it is discarded. While the OEM maintained some spares, replacement transmitters had a 14-22 weeks lead time from their supplier.
Solution:
After years of trying to find another source for transmitters that would survive the testing environment and maintain accuracy, Barksdale’s new BiT product family met the challenge. Barksdale’s Intelligent Transmitter’s thin-film technology design provides better accuracy, down to 0.1%, and long term stability proven in high cycle industrial applications to over a billion cycles. In addition, HART. communication protocol provides some remarkable advantages to several problems and a reduction in time spent locating and tracking transmitters that were up for calibration.
Result:
The OEM put the Barksdale transmitters through a fatigue, shock loading and low/high temperature testing followed by their rigorous calibration process to ensure calibration is maintained. The higher accuracy provided more margin to maintain their minimum 0.25% accuracy, and better long term stability is expected to increase time between trim adjustments. HART protocol allows for digital zero trim and re-ranging to adjust span, eliminating the need for potentiometers that drift with temperature and vibration which further improves the stability of the transmitter. BiT HART transmitter re-ranging capability includes 10:1 turn down which allows the OEM to stock one part that can be reconfigured from 30,000 psi or 10,000 psi range. Additional benefits of HART protocol include the unique device ID and ability to create custom tags to identify each transmitter to help track and identify the physical location of the transmitter in a system. The OEM was able to add a module to their existing data acquisition system to communicate through HART protocol and identify transmitters installed in each test bay from the control system.
Figure 1.
Shows BiT with digital zero trim and re-ranging (Left), and competitors unit with potentiometers to manually adjust zero and span trim (Right Lower). Potentiometers drift with temperature and vibration and require glyptal to lock potentiometers in place (Upper right).
Figure 2.
Shows a BOP test bay. Testing includes high and low temperature testing of the rubber sealing inserts under pressure and shock loading, on large land BOP this included instant application of pressure from 0 to 7,500 psi.
Barksdale, founded in 1949, is a leading manufacturer of highly engineered control products. As a subsidiary of Crane Co., Barksdale has a leading brand position in instrumentation, with focus on General Industrial, Oil & Gas and Transportation end markets. With proprietary technologies, Barksdale’s valves, regulators, pressure switches, electronics, and speed instrumentation products have carved a niche for themselves in demanding applications.
Barksdale is a leading provider of valves and regulators for BOP’s and also provides hazardous area BiT transmitters that can be used to meet API RP 53 BOP testing requirements in the field. Barksdale maintains inventory for popular models to reduce lead time to maximum of 4 weeks.
Have any questions? Contact us today.
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