An engineering firm sought a versatile level measurement solution for fuel storage tanks designed to hold both conventional diesel and, crucially, more chemically aggressive biodiesels like HVO and FAME. The challenge was to identify a sensor that could withstand long-term immersion in these different fuel types without risk of material degradation. This was solved by specifying a submersible hydrostatic level transmitter with carefully selected wetted parts, ensuring a single, robust sensor could provide reliable performance across all current and future applications.
- Application: Continuous level monitoring in 1.6-metre deep horizontal fuel tanks.
- Critical Challenge: Ensuring material compatibility for long-term immersion in both standard diesel and chemically aggressive biodiesels (HVO & FAME).
- Sensor Solution: A submersible hydrostatic level transmitter for simple, direct-in-tank measurement, providing a 4-20mA output.
- Key Material 1 (Cable): An FEP (Fluorinated Ethylene Propylene) sheathed cable was specified for its superior chemical inertness compared to standard PVC, preventing degradation from biofuel exposure.
- Key Material 2 (Seals): FKM seals were selected to maintain the integrity of the sensor housing and protect the sensing element from the ingress of aggressive fuels.
An engineering firm required a continuous level monitoring solution for a series of 1.6-metre diameter horizontal cylindrical tanks used for fuel storage. The initial and most immediate requirement was for compatibility with standard diesel fuel. However, a critical consideration for future projects was the need for the same instrumentation to be fully compatible with different types of biodiesel, specifically Hydrogenated Vegetable Oil (HVO) and Fatty Acid Methyl Ester (FAME). This forward-thinking requirement introduced a significant material compatibility challenge, as biodiesels can be more chemically aggressive than traditional petroleum-based fuels over long periods.
The proposed solution was the LMP307 series submersible level transmitter. This type of sensor is ideal for this application, as it can be lowered directly into the tank to rest at the bottom, providing a continuous and reliable level reading by measuring the hydrostatic pressure of the fuel column above it. The sensor provides an industry-standard 4-20mA two-wire output, which can be easily integrated with a wide range of control and monitoring systems such as a PLC or a digital display.
The key to meeting the customer’s dual-fuel compatibility requirement lay in the careful selection of the transmitter’s wetted parts. While a transmitter with a standard PVC-sheathed suspension cable would be adequate for a diesel-only application, PVC materials can degrade when subjected to prolonged immersion in biofuels like HVO and FAME. This degradation can lead to cracking or swelling of the cable jacket, eventually causing measurement failure and creating a risk of fuel contamination.
To address this specific challenge, the sensor was specified with an FEP (Fluorinated Ethylene Propylene) sheathed cable. FEP is a fluoropolymer that offers outstanding chemical resistance and will not degrade when exposed to these alternative fuels, ensuring the long-term integrity and reliability of the installation. To complement the robust cable, FKM (fluoroelastomer) seals were selected for the transmitter’s housing. FKM provides excellent resistance to oils and fuels, ensuring a secure seal that protects the internal sensing element from the ingress of either diesel or biodiesel. This tailored configuration ensures that a single, versatile sensor can be deployed across all current and future fuel storage tanks without concerns about material degradation or premature failure.
LMP307 Submersible Biofuel Level Transmitter
- SKU ID: s1-lmp307-0006
- Part No: 451-1600-1-1-1-1-5-3-005-000
- Sensor Type: Level only
- Level Sensing Range: 0 to 1.6 mWG
- Reference Type: Gauge / Vented (atm to +P)
- Output Signal: 4-20mA, 2 wire
- Accuracy: 0.5% FS (11-12bit res)
- Installation Type: Submersible probe with flush diaphragm and detachable nose cone
- Housing Material: Stainless Steel 316L
- Diaphragm Material: Stainless Steel 316L
- Media Exposed Seals: FKM
- Cable Type: FEP (70degC max)
- Cable Length: 5
- Cable Length Units: Metres (m)