The Church sees defense of the peace and safety of the spouse who has reason to fear abuse to be so serious that it has spelled out in canon law that spouses in danger have the authority to excuse themselves from the duty to conjugal living on their own authority in order to prevent what could be a dangerous delay:
*Art. 2.
SEPARATION WITH THE BOND REMAINING
Can. 1151 Spouses have the duty and right to preserve conjugal living unless a legitimate cause excuses them.
…
Can. 1153 §1. If either of the spouses causes grave mental or physical danger to the other spouse or to the offspring or otherwise renders common life too difficult, that spouse gives the other a legitimate cause for leaving, either by decree of the local ordinary or even on his or her own authority if there is danger in delay.
**§2. **In all cases, when the cause for the separation ceases, conjugal living must be restored unless ecclesiastical authority has established otherwise.
**Can. 1154 **After the separation of the spouses has taken place, the adequate support and education of the children must always be suitably provided.
**Can. 1155 *The innocent spouse laudably can readmit the other spouse to conjugal life; in this case the innocent spouse renounces the right to separate.
(By my understanding, it is rather unusual for a diocese in the US to have a system set up to get permission from the bishop for a separation. The decision that separation is appropriate is usually made on the authority of one or both spouses, instead, rather than going through the bishop.)