Brand-new, unaged qualified sewer flushing hoses can be straightened smoothly after being stored in a bent state for a period of time. The difficulty of straightening and whether residual creases remain depend on hose material, bent storage duration and aging condition. In contrast, aged and hardened hoses develop fixed permanent bends after bent storage and can hardly be fully straightened; this serves as a core indicator to judge hose condition. Sewer flushing hoses must be bent and coiled for daily storage, which inevitably generates shape memory. Therefore, the hose cannot stay perfectly straight after bending, yet qualified hoses can return to an unfolded state via simple handling without interfering with normal operation.
Hoses of different materials show distinct straightening characteristics. First, household soft PVC sewer flushing hoses are relatively soft with prominent shape memory effects. After short-term bent storage, faint curved creases remain and cannot rebound into straight automatically. Manual segmented stretching and smoothing are required to fully straighten the hose without affecting water flow and dredging operations. If stored bent for several months, creases become more noticeable. Gentle unfolding followed by resting for a while restores flatness without permanent bent residues. Second, polyurethane high-pressure sewer flushing hoses have the best elastic recovery among civil hoses. They possess good resilience. After routine bending and coiled storage, the hoses unfold and rebound automatically once securing restraints are removed, requiring minimal manual sorting. Straightening is extremely easy with almost no residual creases.
Industrial reinforced rubber sewer flushing hoses have the most stable structure. The internal fiber braided layer effectively restricts shape deformation, so stubborn creases will not form after bent storage. Straightening is the simplest; the hose can return to a flat state after basic unfolding and retains its shape even after long-term storage. Worn hoses that have aged, hardened and embrittled behave completely differently. Such hose materials suffer severe toughness loss. Fixed permanent bends form after bent storage, and this deformation is irreversible. Neither manual stretching nor warming can fully straighten them. Bent sections keep protruding and jamming. Forcible pulling and straightening will directly cause pipe wall cracking, damage and peeling, rendering the hose completely scrapped.
Storage practices also affect straightening difficulty. Hoses tightly compressed and bent at fixed points bear concentrated deformation stress, leading to higher straightening difficulty and more obvious residual creases. Hoses coiled loosely and bent moderately bear uniform stress and straighten more easily. Meanwhile, hoses stored in low-temperature environments have reduced material toughness and slightly higher straightening difficulty. After resting at room temperature for a period of time, toughness recovers and straightening becomes simpler.
Simple and effective methods exist to straighten bent sewer flushing hoses. Brand-new and semi-new hoses can be stretched evenly and smoothed section by section, laid flat and rested for 3 to 5 minutes to achieve full straightening. For hoses with minor stubborn creases, unfold them at room temperature and lay flat to allow slow recovery via material elasticity. Violent pulling is prohibited. For aged stiff hoses with permanent bends, replacement is recommended instead of forced repair to prevent safety failures during operation. Avoid fixed-point permanent bends and excessive compression during daily storage, and maintain a loosely and neatly coiled state to fundamentally reduce stubborn deformation and ensure the sewer flushing hose can be straightened easily every time it is used.