Views: 0 Author: Site Editor Publish Time: 2026-08-17 Origin: Site
Within the Xinda XDFC flange machine family, the XDFC610 (50–610 mm, 1 kW servo, 220 V), XDFC1000 (100–1000 mm, 2 kW servo), and XDFC2000 (800–2000 mm, internally clamped for extra-large flanges) all follow the "electric drive + external clamp / internal clamp" route, serving medium and large bore flanges. But in the small-bore segment of DN25–DN250 — process piping flanges, instrument root valves, pump body flanges, valve seats, and compressor flanges — there is a blind spot that the electric models "cannot reach": low unit value, scattered distribution, no power or spark prohibition in pipe racks, and on-site machining that is not cost-effective.
Flanges in the DN25–DN250 range represent a "fragmented" class of working conditions in industrial fields:
First, large quantities and scattered distribution. A medium-scale petrochemical unit often has thousands of process piping flanges below DN250; instrument root valves and tracing pipe flanges are even denser. Sending a single flange out for subcontracting machining costs more in freight than in the repair itself.
Second, no power or spark prohibition on site. Pipe rack levels, pipe tunnels, explosion-proof zones, lower decks of offshore platforms, and clean areas — drawing 380 V industrial power in these locations requires approval and wiring, and the electrical sparks from electric tools are a red line in explosion-proof zones.
Third, unit value too low to amortize equipment cost. An XDFC610 could do the job, but deploying a dedicated electric model just for DN25–DN100 small flanges is over-configured for a small maintenance team.
Fourth, intact bore with adjacent pipes on the outside. Most DN25–DN250 flanges are pipe flanges, valve seat flanges, and pump body flanges — with intact bores and outer edges often adjacent to pipes or components. Internally clamping from the bore and expanding outward fits perfectly; a large external-clamp machine cannot fit its "legs" in.
The XDFC250's solution — remove all electrical components entirely, and let the hand crank be the power source.
Parameter | XDFC250 |
|---|---|
Machining diameter range | 25–250 mm |
Mounting method | Internal clamp (ID mounted) |
Spindle speed | 0–100 r/min (hand-cranked) |
Depth of cut | 0.2 mm |
Flatness | 0.10 mm |
Surface roughness | Ra 3.2 |
Feed method | Manual |
Machine weight | 15 kg |
Translated into field language:
25–250 mm machining range = fully covers DN25 through DN250 (1″–10″), capturing the "small-bore dense zone" of process piping flanges, instrument root valves, pump body flanges, valve seats, and compressor flanges.
Internal clamp mounting = support legs expand outward from the flange bore, taking the flange itself as the datum — no contact with the outer wall, no clamping on the outer circle. Friendly to blind flanges, valve seats, pump body flanges, and instrument root valves; zero contact with the outer wall means no metal scratches.
0–100 r/min hand crank = the hand crank drives the spindle through mechanical transmission; the veteran operator's cranking rhythm is the cutting rhythm. The low-speed, high-torque characteristic perfectly matches the reasonable cutting speed for small-bore sealing face restoration.
Depth of cut 0.2 mm = the reasonable cutting depth for sealing face restoration; in two passes (0.15 mm to peel the hardened layer + 0.05 mm finishing cut), Ra 3.2 is reliably achieved.
Flatness 0.10 mm = meets the precision baseline for flange sealing face restoration — the industry consensus is that post-machining flatness error must not exceed 0.1 mm to guarantee sealing.
15 kg total weight = disassembled into an aluminum alloy case and carried by one person; can be brought into platform engine room decks, pipe tunnels, and unit pipe rack levels. No servo motor, no electric cabinet, no handheld control cable.
Many people see "hand crank" and instinctively think "simplified version" or "low-spec version." This is a misreading of the XDFC250 — in scenarios involving small bore, no power, and confined spaces, hand cranking is an active choice, not a cost compromise:
The solution for no-power scenarios. Petrochemical units, lower decks of offshore platforms, underground pipe racks, explosion-proof workshops, and clean areas — temporarily drawing power in these places requires approval, wiring, and explosion-proof certification. The hand-cranked machine removes all electrical components, making the tool itself a low-risk device and easing work permit approval.
Natural match for low-speed, high-torque. The cutting linear speed for small-bore flange sealing face restoration is inherently low; the 0–100 r/min hand-crank range perfectly covers the reasonable cutting speed. Cranking force is controlled by the wrist; with a 0.2 mm depth of cut in two passes, the Ra 3.2 surface grade is reliably delivered.
Human-factor engineering for single-operator use. Hand-crank drive, manual feed — one person carries the case in, one person clamps, one person operates. In confined spaces like pipe racks, pipe tunnels, and clean areas where "turning around is difficult," two or more people become a burden; one person is instead an advantage.
Compliance dividend of spark-free operation. Explosion-proof zones, clean areas, electronic specialty gas stations — the hand-cranked machine has no electrical spark risk, eliminating the need for hot-work permits or electrical tool explosion-proof verification. One less external variable means one less verification risk.
The XDFC250's 25–250 mm range covers densely in "small-bore, no-power, confined space" scenarios:
Petrochemical Units
DN25–DN200 process piping flange and instrument root valve flange restoration; can be done under pipe racks without power, without stopping the main unit. Root valve flanges for tracing pipes, sampling pipes, and impulse lines — low unit value but high quantity — make the XDFC250 hand-cranked machine the optimal cost-performance solution.
Marine Piping Systems
Small-bore flanges for bilge pipes and freshwater pipes; can be worked in pipe tunnels without power. Internal clamping does not damage the inner wall, and the lightweight equipment can be carried into narrow pipe tunnels, eliminating the need to cut pipes and send them ashore.
️ Field and Emergency Repairs
Emergency repair of small flanges on field pipelines and temporary gas supply points; operation is possible without a generator — the hand crank is the power source.
The division of labor within the Xinda XDFC flange machine family is now clear:
Bore ≤ 250 mm, and site has no power / spark prohibition / confined space → Choose XDFC250, the 15 kg hand-cranked machine.
Bore ≤ 350 mm, wanting automatic feed for labor savings → Choose XDFC350, with hybrid hand-crank + automatic feed, aluminum body approx. 18 kg.
Bore 50–610 mm, site has 220 V → Choose XDFC610, the electric model with high efficiency.
Bore 100–1000 mm, site has 380 V → Choose XDFC1000.
Distilled from the experience of piping teams and clean-area maintenance crews:
① Clean the bore to bare metal.
The internal clamp legs grip the flange bore. Rust, old gasket adhesive, and medium coke deposits, if not cleaned, cause uneven leg force and eccentric rotation center. Before installation, use a wire brush + decoking agent to clean the bore, then run the hand crank at low speed for one revolution to check tool tip runout; if it exceeds 0.02 mm, readjust the jacking screws.
② Don't be greedy with depth of cut layering.
0.2 mm depth of cut is the upper limit; actual recommendation is a first pass of 0.15 mm to peel the hardened layer and alkaline corrosion layer, followed by a second pass of 0.05 mm for finishing to achieve Ra 3.2. Cranking force relies on the wrist; forcing beyond 0.2 mm makes cranking difficult and causes the tool tip to dig into the surface. Sanitary-grade sealing faces must avoid dug marks.
③ Clear chips promptly.
Hand-crank speed is low and chips form short curls; after two revolutions, clear with a wire brush once, to prevent curled chips from jamming between the tool arm and the flange face, which would deflect the tool tip in the next revolution. For clean-area work, spread a piece of non-woven cloth or use a magnetic collection box; after each curl is cut, collect it to prevent stainless steel chips from falling into the pipe.
④ Lock in 0.10 mm flatness from the alignment stage.
The XDFC250's 0.10 mm flatness is the maintenance-grade on-site restoration baseline, corresponding to the industry consensus that "post-machining flatness error must not exceed 0.1 mm to guarantee sealing." This precision is locked in from the internal clamp centering + alignment step — when micro-adjusting the jacking screws, use a dial indicator to measure the runout of the sealing face, and lock the support legs only after radial runout is controlled within 0.03 mm.
(This article is compiled from publicly available corporate materials and industry information for reference only. Specific product information and service terms are subject to the official release of the enterprise.)
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