Magnaflux 7HF Oil-Based Visible Magnetic Particle Aerosol

Black visible magnetic particles in an aerosol for field MT

Magnaflux 7HF is an oil-based magnetic particle suspension in an aerosol can for the non-fluorescent (visible) wet method of magnetic particle testing. It locates fine and medium discontinuities on finished parts. The black particles build up heavily at leakage fields, giving clear indications in ordinary light, and the manufacturer says particle size is the smallest on the market (mean particle size below 2 microns).

The aerosol format is aimed at field testing, spot inspections and places where bulk processing is impractical. A wide spray pattern and an upgraded 360 degree sprayer let an inspector cover large areas of tubing, piping and large structures. The data sheet notes that 7HF is often used with WCP-2 white contrast paint to improve contrast and sensitivity on bright or dark surfaces.

Features

• 360 degree aerosol sprayer with a broad, even spray pattern
• Clear indications under visible light, no UV lamp needed
• Heavy particle buildup and great particle mobility
• Superior surface wetting, very low toxicity and low odour
• Oil-based formula that protects parts and equipment against corrosion
• Very small particle size for fine indications

Technical specification

The data sheet adds that particle integrity and mobility may decline beyond the temperature limits, and that for a vehicle conforming to AMS 2641 the minimum temperature is 6 C.

Selection guide

Choose 7HF when the surface can be viewed in normal light and the job is a field check rather than a production line: pipe welds, vessel seams, structural nodes and in-service parts. For very fine flaws on critical parts a fluorescent suspension such as 14AM gives more contrast under a UV lamp, but needs a darkened area. The 7HF sheet lists only the aerosol pack.

Operating instructions from the data sheet

Use with an appropriate magnetisation procedure and equipment, on parts that are clean and dry. The listed steps are: use in a well-ventilated area; apply WCP-2 before 7HF for best contrast; shake the can well and occasionally during application; hold it 7 to 9 inches (18 to 24 cm) from the area; spray using the continuous or residual method until the area is covered; and inspect under visible light.

To verify particle concentration, perform a sensitivity check using a known test standard before inspection. Parts must be properly demagnetised before cleaning for easy particle removal, and may be given a temporary protective film if longer corrosion protection is needed. Store in a ventilated area away from magnetising equipment and heat, because strong magnetic fields, age and heat can affect particle redistribution.

Applications in Gulf industry

The sheet lists machined parts, light surfaces and difficult-to-reach areas, with defect examples such as inclusions, seams, shrink cracks, laps, flakes, welding defects, grinding, quenching and fatigue cracks. Typical uses in the region include pipeline and tank weld inspection, crane and lifting equipment checks, and shutdown inspections of heat exchanger shells and structural steel, normally with a yoke such as the Magnaflux Y-7.

Planning a field inspection with 7HF

Aerosol magnetic particles are usually bought for a defined job, so plan the whole kit before ordering. Besides the 7HF cans, the data sheet points to a magnetising device, WCP-2 white contrast paint for better contrast, a known test standard for the sensitivity check and a means of demagnetising the part afterwards. The printed usage temperature is 6 to 48 C, so on hot Gulf surfaces check the part temperature before starting, because particle mobility can decline outside the limits.

Storage and handling

Store the cases at 10 to 30 C in a ventilated area, away from heat and away from strong magnetising equipment, which the sheet says can affect particle redistribution together with age and heat. Shake each can well, keep a record of batch numbers and use the Safety Data Sheet for protective equipment and disposal advice.

Information needed for a quotation

Send the part number 01-1580-78, the number of cases of twelve, the delivery location in Oman or the GCC and any specification the shipment must reference. If WCP-2 contrast paint, a yoke or a fluorescent suspension is also required, list it in the same request.

Related items

See the Y-7 yoke, 14AM fluorescent suspension and 20B premix pages, and the Non-Destructive Testing (NDT) category. WCP-2 contrast paint is the accessory named in the 7HF sheet.

Ordering note: 7HF is listed only as a case of twelve aerosol cans, so state the quantity in cases. If you also need WCP-2 contrast paint or a magnetizing device, list them in the same request so that compatibility with your written procedure can be reviewed together with the particle suspension.

Documents and quotation

The manufacturer data sheet is attached to this page and all values are from it. Confirm the specification list against your procedure before ordering; Seven Star LLC is an independent supplier in Muscat.