(6)　Handling instructions

① In the interest of stable performance, it is recommended that molded rings be used. Molded rings not only contribute to the reduction of time required for assembling, but also play a critical role in maintaining a favorable sealing property. When coil type packing is used as it is, the tightening force is hard to convey to the inner depth. As a consequence, a substantial difference will arise between the gland follower side and bottom side of the stuffing box, which may cause stress relaxation, resulting in leakage.
②Check the shaft diameter and the stuffing box inner diameter.
③ If coil type packing is unavoidably used, select appropriate packing with the same nominal packing size as the width of stuffing box.
④ If packing with a suitable size is unavailable for a given stuffing box, a 9.5 mm wide for example, select packing with a nominal size of 10 mm, and adjust the size in the following way. That is, first lay down the packing on a flat plate, and uniformly press it by rolling a round bar, so that it may be 0.5 mm smaller than the width of the stuffing box, namely 9.0 mm in this case, before using it.

(b) Cutting
When using coil type packing, set the length per one ring of packing in the following way, and cut it at an appropriate angle so as to allow no gap when aligning them together.
L＝1.62〜1.65（d＋D）
where,
L : Length per one packing ring (mm)
d : Shaft diameter (mm)
D : Stuffing box inner diameter (mm)

(c) Installation of packing

① Remove all pieces of old packing. Using a packing tool will facilitate the work, but care shall be exercised so that the packing tool may not damage the shaft.
② For installation, make sure of the number of pieces of packing, as well as the combination of the types of packing.
③ Install one ring at a time. Seat each ring firmly, making sure it is fully seated before installing the next ring. Joints of successive rings should be staggered and kept 90º to 120º apart.

(d) Tightening and adjustment
(i) For pumps

① Upon installation of packing, tighten nuts alternatively on the symmetrical position so as to avoid uneven tightening. The resulting tightening stress should be on the order of 1 to 2 MPa.
② Apply liquid and wet the packing sufficiently and check if it is well lubricated with leaking liquid before retightening. At this time, do not tighten or unfasten the nuts rapidly, but adjust them uniformly by turning each of them by one or one half pitch of the nut head (i.e., 1/6 to 1/12 rotation) under visual check.

(ii) For valves
③ Upon installation of packing, tighten nuts alternatively on the symmetrical position so as to avoid uneven tightening. For tightening stress, see paragraph (3)-(c) “Design criteria” – “Standard tightening stress.”
④ Retighten, if leakage occurs. In this case, tightening after reducing the inner pressure to zero will be effective. Also take care so as to avoid uneven tightening or too much tightening.

(e) Notice for storage
(i) Do not allow packing to deteriorate
Since some packing materials are affected by direct sunshine, oxygen and ozone in the air, and high temperature or humidity, packing should be stored in a cool and dark place as far as possible to avoid deterioration. Anti-corrosion treated packing, in particular, must not be stored in acid atmosphere or humid conditions, or in locations subject to high temperature.

(ii) Prevent dust adhesion
Foreign substances like dust may adhere on the products during storage or due to carelessness in handling. Dust, once adhered, cannot be removed completely with ease, and will give damage to the shaft, causing leakage to result. Thus, adequate care is needed.