Inspection methods for glass-lined equipment (glass-lined reactors)

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Enameled equipment is mostly used in harsh corrosive environments, so quality inspection of the products must be very strict. The inspection requirements are determined based on the grade specifications of the product itself; the inspection methods are shown in the table below. Once the products pass the inspection, they can be assembled or packaged for shipment. For components that require assembly, inspection is carried out after assembly; only when the entire component meets the standards can it be considered a qualified product and packaged for storage. Before being sold, the equipment should be left undisturbed for more than half a month to eliminate any residual stresses. **Items, Technical Indicators, and Testing Methods**

**Porcelain layer thickness:** 0.8–2.0 mm. Measure using a non-magnetic thickness gauge in accordance with GB7991–87.

**Voltage resistance:** Must withstand 20,000 V (DC) without breakdown. Test using an AC spark generator as per GB7993–87.

**Pressure resistance:** Must meet design requirements. Conduct testing via hydraulic pressure tests following GB7994–87.

**Appearance quality of the porcelain layer:** The color should be uniform; the surface must be smooth, with no chipping, fish-scale cracks, or hidden bubbles. There should be no more than three foreign particles on the outer surface of the tank body and lid; each particle must not exceed 8 mm² in size. The distance between any two particles must be at least 100 mm. Inspection is carried out under bright lighting or using a 100-watt low-voltage lamp positioned 600 mm away from the surface; observations and records are then made at a distance of 600 mm from the porcelain surface.

**Deformation tolerance:** The difference between the maximum and minimum diameters of the flange must not exceed 0.1% of Dg. Measure the maximum and minimum outer diameters using a measuring tape; this difference represents the degree of ovality.

**Flange flatness:** Allowed deviation must not exceed 0.3% of Dg. Use a feeler gauge to determine the maximum gap between the flange surface and a reference plane; this value indicates the degree of flatness.

**Horizontal level of the flange surrounding the agitator opening:** Allowed deviation must not exceed 10%. Place the lid so that it lies horizontally; position a straightedge over the flange surrounding the agitator opening. Using a right-angled triangular ruler, measure the vertical distance from the platform around the flange to the surface of the straightedge. Calculate tga ≈ Δhmax/Dg based on the highest and lowest measured values.

**Width of the flange’s clamping surface:** Must be at least 10 mm. Place a straightedge no thicker than 5 mm across the flange diameter and rotate it 180°; measure the width of the clamping surface (considering only those areas where continuous gaps remain ≤0.5 mm).

**Radial runout at the upper end of the agitator:** For packing seals, this value must not exceed 0.30 mm. Install the agitator on a test frame and rotate it; attach a dial indicator to the contact surface between the agitator’s main shaft and the stuffing box to perform measurements.

**Straightness of pipes [including thermometer sleeves]:** Allowed deviation must not exceed 0.3% of L. Use a straightedge to measure the maximum gap between the pipe and the straightedge.

Specific requirements are outlined in standards ZB G94004–87 and ZB G94005–87.