Equipment Guide · Manifold, Reducers & Pressure Rating
The cargo manifold is the one place cargo ever crosses the ship's side — a row of standardised flanges amidships where the terminal's arm or hose bolts onto the ship's lines. Everything about a transfer funnels through it: the size of the connection, the rate the pipework can actually pass, the pressure the weakest component can stand. Tap a step or press "Play" to follow the cargo from the jetty line, up the hose, through the reducer and presentation flange, and into the ship's crossover — then take the terminal's phone call yourself in the simulator: they propose a hose and a rate, you accept or counter.
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A terminal asks for 7,100 m³/h through a single 20″ flexible hose. Start with the arithmetic on the hose itself: a 20″ bore is an area of ≈0.203 m², so v = (7,100 ÷ 3,600) ÷ 0.203 ≈ 9.7 m/s — comfortably inside a 12 m/s ceiling, so the hose is not the limit.
But a hose passing the rate does not mean the ship can. Check, in order: (1) the ship’s maximum rate per manifold from the cargo manual / Q88 — if the Q88 says, say, 4,700 m³/h per manifold, a single connection cannot take 7,100 no matter how big the hose; (2) the manifold flange and hose pressure rating; (3) vent / IG capacity ≥ 125% of the rate (the same margin from the IG-system guide, seen from the other side); (4) the topping-off rate and ESD closure time, agreed in writing. The verdict: the hose is fine; the ship is the limit. Accept 7,100 only if the cargo manual allows that rate through that connection and the venting can breathe it — otherwise split it across manifolds or reduce the rate.
The terminal offers a hose size and a loading rate; you know your own ship. Set the hose bore, your ship line bore, the number of connections, your ship's line-velocity ceiling and the requested total rate, and judge the request. Fixed for this drill: hose rated 15 bar, manifold flange ANSI 150 ≈ 19 bar, total venting capacity 9,000 m³/h. The velocity ceiling is yours to set — your cargo manual / Q88 gives the real figure. Accept only what the whole chain can pass.
Limits for this drill — velocity ceiling 12 m/s (adjustable — your cargo manual sets it) · hose rated 15 bar · flange ANSI 150 ≈19 bar · vent ceiling 9,000 m³/h total.
The pressure climbs with the square of the velocity, and the velocity lives in the smallest bore — so a small hose or a small ship line punishes a big rate twice over. Splitting the rate across more connections drops the per-connection velocity, but the total still has to clear the vent ceiling: the tanks must push vapour out exactly as fast as cargo comes in.
Set the hose, ship line, connections and rate, then press Start — the terminal proposes, you dispose.
Working principle — explained in our own plain words with our own schematic from general marine knowledge (not copied from any OEM manual). Conceptual; varies by ship/model. Reviewed and verified by a Master Mariner.